There are several issues that need to be pointed out:
1. If your patent is ABCD, the earlier patent applied by the other party is ABC;
In this case, your patent belongs to the subordinate patent. When granting a patent, as long as it is improved on the basis of previous patents and meets the requirements of novelty, creativity and practicality, a patent can be obtained.
But in this case, once you manufacture, use, sell, promise to sell or import the patented product (ABCD), you will definitely infringe the patent of the other party (ABC); As the "patent egg" answered, the enforcement right can be obtained through compulsory license, but there have been no cases of compulsory license since the implementation of the patent law in China, and the reasons are not detailed. The most reasonable way is to cross-license each other.
2. The principle adopted in patent infringement litigation in China is the principle of compensation, that is to say, how much the patentee loses and how much the infringer compensates (of course, the amount must be supported by relevant evidence). There is no so-called malicious infringement in China, which is different from the United States. Once malicious infringement is determined, there will be several times punitive damages in the United States.