On 10 November 2025, the China National Intellectual Property Administration (CNIPA) released the latest amendments to the Guidelines for Patent Examination. Among other changes, the amendments revise the wording of the ne bis in idem principle in invalidation proceedings, replacing “the same grounds and evidence” with “the same or substantially the same grounds and evidence.” On its face, this appears to be a mere linguistic refinement by adding the notion of “substantially the same.” However, from a practical perspective, this change effectively broadens the scope of application of the ne bis in idem principle in patent invalidation proceedings.
I. Provisions on the Ne Bis in Idem Principle in Invalidation Proceedings
Article 70(2) of the Implementing Regulations of the Patent Law provides: “Where, after the Patent Reexamination Board has made a decision on a request for invalidation, another request for invalidation is filed on the same grounds and evidence, the Patent Reexamination Board shall not accept the request.” Correspondingly, the amended Guidelines for Patent Examination, Part IV, Chapter 3, Section 3.3(3) further state:
“For a patent right involved in an invalidation case on which an examination decision has already been made, if a request for invalidation is filed again on the same grounds and evidence, the request shall not be accepted or examined. However, if the grounds for invalidation (hereinafter referred to as ‘invalidation grounds’) or evidence in the later request were not considered in the earlier invalidation decision due to a time limit or other reasons, such a request does not fall within the above circumstances of non-acceptance and non-examination.”
The ne bis in idem principle serves, on the one hand, to avoid contradictory examination decisions being made on the basis of the same facts and grounds, thereby preserving the stability and authority of CNIPA’s decisions. On the other hand, it enhances the efficiency of administrative patent procedures, prevents unnecessary consumption of administrative resources, and reduces the burden on patentees in having to defend repeatedly against duplicative challenges.
In the explanatory notes issued at the consultation stage of the latest amendment to the Guidelines, CNIPA expressly clarified the legislative intent behind revising “the same grounds and evidence” to “the same or substantially the same grounds and evidence.” The purpose is to cover scenarios where, “for example, only minor formal adjustments or variations are made to the invalidation grounds or evidence, but they are in substance the same in terms of legal and factual content,” which should still fall within the regulatory ambit of the ne bis in idem principle. In other words, the amended Guidelines are intended to more clearly capture situations where there is no substantive difference, despite superficial changes in form.
II. Potential Issues Arising from the Ne Bis in Idem Principle
The ne bis in idem principle has its origins in civil procedure and is a fundamental principle aimed at preventing repetitive litigation, conserving procedural resources, and avoiding parties being drawn into endless litigation. In this sense, it is inherently beneficial. However, China’s patent invalidation system has certain particularities. In light of public interest considerations, a request for invalidation is not limited to specific interested parties; instead, any person may file an invalidation request, and may do so multiple times without a formal numerical limit.
Against this backdrop, the ne bis in idem principle in patent invalidation does not adopt the civil procedure requirement of “the same parties.” This opens up the possibility—intentionally or unintentionally—of strategic use or even abuse, whereby strong invalidation grounds or evidence are “consumed” in a way that ultimately benefits the patentee.
A typical scenario is that a patentee arranges for a third party to file an invalidation request so as to “sacrifice” potentially strong grounds or evidence. If that third party conducts the invalidation proceedings in a perfunctory manner, the otherwise powerful grounds or evidence may not be fully developed or effectively relied upon, and are thus “wasted.” When other parties later file invalidation requests, they may be precluded from re-using the same or substantially the same grounds and evidence due to the operation of the ne bis in idemprinciple.
Apart from such deliberate “self-sacrifice” strategies, an earlier requester may, due to lack of capability or insufficient preparation, also inadvertently waste strong invalidation grounds or evidence.
Because these “self-sacrifice” situations are rarely apparent on the face of invalidation decisions or published court judgments (subsequent requesters who are aware of an earlier decision will generally avoid repeating exactly the same or substantially the same grounds and evidence), such strategies are not easy to identify from case texts. Nevertheless, they are familiar to, and frequently discussed among, practitioners in the field.
By expanding the standard from “the same grounds and evidence” to “the same or substantially the same grounds and evidence” in the present amendment to the Guidelines, the theoretical scope of non-acceptance and non-examination has indeed been broadened, which understandably gives rise to heightened concern within the profession.
III. What Constitutes “Substantially the Same” Grounds or Evidence
As to how “substantially the same” should be understood, the consultation draft explanation of the amended Guidelines provides only a general illustration, namely situations where “only minor formal adjustments or variations are made to the invalidation grounds or evidence, but they are in substance the same in terms of legal and factual content.” In practice, however, earlier judicial decisions and invalidation decisions have already provided some indicative standards.
For instance, with respect to the same prior art document, different embodiments or distinct technical disclosures within that document will typically be regarded as different evidentiary content. In the (2024) Zuigao Fa Zhi Xing Zhong No. 258 case concerning an administrative dispute over the invalidation of a utility model patent, the Supreme People’s Court held that in the earlier Decision No. 50886 on invalidation, the requester had only submitted a Chinese translation of selected paragraphs from Exhibit 1 (a U.S. patent document), which did not include any disclosure of the specific structure of the suction strip device 12. By contrast, in the subsequent invalidation proceedings, the requester supplemented the record with a Chinese translation of the “use” portion of Exhibit 1, which specifically included the technical details of the structure of suction strip device 12. Consequently, the version of Exhibit 1 relied upon in the challenged decision contained additional substantive content as compared to the version of Exhibit 1 in Decision No. 50886, and thus the two could not be regarded as exactly the same evidence.
Moreover, differences in how evidence is combined, the way in which technical motivation or teaching is derived, and the nature of the improvement rationale can also give rise to different invalidation grounds. In the same case, the requester also argued on appeal that Exhibit 6 had been impermissibly reused. The Supreme People’s Court found that because the content of Exhibit 1 relied upon in the later decision had changed, the distinguishing technical features had also changed accordingly. As a result, the factual basis for assessing whether Exhibit 6 provided a relevant technical teaching was no longer the same as in the earlier invalidation proceeding. On that basis, re-evaluating the combination with Exhibit 6 in the later case did not violate the ne bis in idem principle.
Particular attention should be paid to the application of ne bis in idem to “non-three-characteristics” grounds, especially invalidation grounds based on non-compliance with Article 26(3) and (4) of the Patent Law.
In Invalidation Decision No. 587385, a later invalidation requester again argued that the description did not sufficiently disclose the technical solutions of claims 1–3. The requester maintained that the description failed to disclose the stereochemical configuration of crizotinib per se in claims 1–3 (referring to the stereochemical confirmation methods that are common general knowledge in the art as shown in Evidence 5) and its effects, as well as the structure and effects of the polymorphic forms of the compound.
The CNIPA panel held that although the later requester had submitted new Evidence 5, the mere appearance of new evidence in a later case does not automatically justify re-examining facts already established in an earlier decision. Specifically, Evidence 5 was a technical guidance document on quality control of chiral drugs published after the filing date, which discussed several principal methods for stereochemical confirmation, including single-crystal X-ray diffraction, circular dichroism, optical rotation, and nuclear magnetic resonance. The earlier decision had already addressed the issue of confirming the stereochemical configuration of crizotinib. The newly submitted Evidence 5 in the later case shared the same probative purpose as Evidence 5 and Evidence 6 in the earlier decision and was therefore likewise insufficient to overturn the facts established therein. As a result, the requester’s invalidation grounds relating to sufficiency of disclosure and the cited documents were held to fall within the scope governed by the ne bis in idem principle.
This illustrates that, with respect to invalidation grounds under Article 26(3) and (4) of the Patent Law, CNIPA does not re-open examination merely because “new evidence” is presented at a procedural level. Rather, it focuses on whether the new evidence is capable of undermining or overturning the factual findings already made in the earlier decision. In essence, this approach shifts the focus toward substantive differences in invalidation grounds, rather than merely formal changes. Compared with the example given in the Guidelines’ explanatory notes—where only minor formal adjustments are made—this marks a clear movement toward substantive scrutiny. From a practical standpoint, CNIPA’s assessment of whether new evidence is sufficient to overturn the earlier factual findings is, in effect, a further substantive re-evaluation of the corresponding invalidation grounds.
IV. Recommendations for Invalidation Requesters
The above practice shows that both the examining authority and the courts have long tended to apply a “substantially the same” standard when interpreting ne bis in idem. The latest amendments to the Guidelines mainly serve to formalize and clarify this approach at the textual level. As regards lack-of-novelty and lack-of-inventive-step grounds, if in a later proceeding the evidence, manner of combining evidence, or technical teaching differs in substance from what was considered in the earlier decision, such grounds will generally not be excluded from examination solely on the basis of the ne bis in idem principle.
From the standpoint of practical impact, ne bis in idem warrants the greatest attention in relation to invalidation grounds based on Article 26(3) and (4) of the Patent Law.
In technical fields with relatively low predictability, such as chemistry and biopharmaceuticals, whether the description is sufficiently disclosed (Article 26(3)) and whether the claims are supported by the description (Article 26(4)) are often central issues in both examination and invalidation. By contrast, in fields with higher predictability, such as electronics, communications, and mechanics, Articles 26(3) and (4) have historically received comparatively less emphasis. In recent years, however, CNIPA has clearly intensified its scrutiny under these two provisions. For example, in Reexamination and Invalidation “Top Ten Cases” No. 563221, and in invalidation cases No. 563247 and No. 562899 relating to major lithium battery litigation, the patents at issue were all invalidated on the ground of insufficient disclosure in the description.
Once, in a first-round invalidation proceeding, CNIPA has rendered a decision favorable to the patentee on grounds under Article 26(3) or (4), any subsequent attempt to challenge the patent on similar grounds is highly likely to be barred by the ne bis in idem principle. Accordingly, invalidation requesters should, at the outset of a case, conduct a thorough and careful assessment of potential invalidation grounds under Article 26(3) and (4). If they decide to rely on these provisions, they should be prepared to “go all in” from the first invalidation attempt—deploying their arguments, evidence, and case strategy as comprehensively as possible at the initial stage.
