This paper combs and analyzes the drug patent infringement cases in China from 1995 to October 2020. The empirical analysis was carried out from the dimensions of the year of case acceptance, the subject of litigation, the type of drug involved, the level of adjudication and the case conclusion. According to the above statistical analysis, the number of patent infringement cases of chemical drugs in China is the largest, accounting for 53.3%, followed by that of traditional Chinese drugs and biological drugs in China, accounting for 30.7% and 16%, respectively. In drug patents in China, the "basic patents" of drugs are mostly held by foreign companies that own the original patented drugs. They build patent portfolio around the "basic patents" and actively use patent litigation strategy. Combined with empirical research, this paper discusses the specific strategies of patent work of pharmaceutical companies in China.