Challenges and solutions for Chinese patent applications

By Wu Li, Zhang Xiaoning, and Yang Jian, Lifang & Partners

With constant perfecting of the intellectual property (IP) system, China has been making significant strides in IP protection. However, in practice, rights holders still face many challenges and difficulties, including obtaining ideal patents.

This article, based on practical experience in both patent protection and prosecution, introduces challenges and difficulties arising in the patent prosecution process – as well as strategies for how best to deal with them – in the fields of biopharmaceuticals, communication standards and artificial intelligence (AI).


Wu Li, Lifang & Partners
Wu Li
Senior Partner
Lifang & Partners
Tel: +86 10 6409 6099

Biopharmaceuticals is an experimental discipline where fully documented experimental data is crucial for obtaining stable patents in patent applications. Patent examination is particularly rigorous in its requirements for experimental data, with some standards bordering on stringent.

Based on such data standards, the scope of a granted patent is consequently very limited in the biopharmaceutical field. Usually, examiners confine the scope the claims seek to protect to the disclosure contained, especially in the biological sequences, compositions and processes.

When submitting a patent application, relevant experimental methods and data should also be fully disclosed in the embodiments to avoid an overly narrow patent protection scope due to support issues for claims.

In light of this situation, courts have in recent years been actively exploring the doctrine of equivalence in patent infringement disputes in the biopharmaceutical field. Given the protection scope of biopharmaceutical patents is usually quite narrow, it is highly recommended that rights holders consider how to pave a foundation for utilising the doctrine of equivalence during the patent prosecution process, in order to gain greater advantages in the subsequent patent enforcement process.

For example, when drafting patent applications for composition, add various embodiments of component combinations and their effects in the specification, designing the claim set in a hierarchical manner and covering foreseeable active ingredients and excipients in different claims to maximally broaden the protection scope.

Note also that, based on different ways of interpreting the technical solutions in judicial practice, even if the sequence claim is closed-ended, some sequence beyond the scope of the claim may still be regarded as equivalent sequence.

Therefore, it is advisable to describe the principles as much as possible in the drafting. For example, as to the conservative functional regions of specific sequences, consider providing more embodiments or experimental data to prove that when there are additional sequences at one or both ends of the sequence, similar activities are still retained. This creates opportunities for subsequent arguments for equivalence.


Zhang Xiaoning, Lifang & Partners
Zhang Xiaoning
Lifang & Partners
Tel: +86 10 6409 6099

Technical standards are important means of promoting technologies and their industrialisation. In recent years, with an increasing number of infringement lawsuits involving Standard Essential Patents (SEPs), the question of how to obtain valid SEPs has become a key focus of China’s patent prosecution practice.

To have valid and stable SEPs in the future enforcement process, applicants are recommended to adhere to at least the following principles during the prosecution process:

(1) The coverage principle. An SEP should always correspond to a standard protocol. During patent drafting, such factors should be taken into consideration as the proposed technology for which a standard protocol is yet to be formed might be subject to partial amendments, extensions and substitutions due to integration and compromise during the standardisation process.

Consequently, a broader protection scope should always be sought when drafting the independent claim, while encompassing the invention points and guaranteeing the integrity of the technical solutions are to be firstly satisfied, to ensure technical solutions ultimately adopted by the standard can be covered. As for dependent claims, they should be arranged in a way to effectively expand the technical solutions from different dimensions.

(2) The flexible principle. The proposed technology would usually undergo certain alterations during the standardisation process. Therefore, it is suggested that applicants fully utilise opportunities for amendments during the prosecution process to reasonably amend the claims within the original scope of disclosure, to eventually achieve the required correspondence between the granted patent and standard protocol.

If the granted claims are not sufficiently corresponding to the technical standard, it is necessary to consider pursuing divisional applications to further obtain patents with higher correspondence.


As AI continues to scale new heights, the number of patent applications related to AI has rapidly increased. Although AI patents are not presently so frequently involved in patent infringement disputes, strategies of how to best design and prosecute such patents to obtain maximum protection in accordance with China National Intellectual Property Administration examination practices have garnered great attention.

AI technologies are closely associated with algorithm models and computing chips. The algorithm model implemented through a computer program is the main source of AI innovation. However, if the innovation point merely lies in the improvement of the algorithm model, it would be non-patentable subject matter under Chinese patent law.

To meet the requirements for patentable subject matter, the algorithm model needs to be closely integrated with specific technique features of the technical fields and application scenarios, which may narrow the protection scope of the claim, and should be carefully weighed.

In addition, if the technical innovation point lies in fine-tuning the algorithm model and then applying it in different technical fields or application scenarios, its inventiveness may need to be further evaluated.

To demonstrate the inventiveness level of such technical solutions, an effective strategy during application drafting is to fully explore and stress the physical advancement and significance that can be achieved by the fine-tuned algorithm model through data processing in the pertinent technical field, rather than solely focusing on the advance of the mathematical process, or simply describing it as a black box.

Wu Li is a senior partner at Lifang & Partners. He can be contacted by phone at +86 10 6409 6099 or by e-mail at
Zhang Xiaoning is a partner at Lifang & Partners. She can be contacted by phone at ++86 10 6409 6099 or by e-mail at
Yang Jian, a senior counsel at Lifang & Partners, also contributed to the article

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