Abstract: Patent litigations have increased rapidly in recent years, which have a profound impact on technology innovation and industry competition. Taking smartphone industry with frequent patent litigations as the research sample, the social network analysis has been employed to construct patent litigation network. The relationships between litigants are revealed and the differences of litigants are compared and analyzed. Then hierarchical cluster analysis has been used to analyze the key features of litigants quantitatively, and the types of litigants are defined. The results reveal that litigants have shown significant differences in the frequency of prosecuting and prosecuted, as well as network location. Accordingly, litigants have been divided into four types. Besides the leading enterprises and catch-up ones, the other two types of litigants have been ignored. They are professional organizations specializing in patent operation and have become important prosecutors. Chinese enterprises should pay great attention to them in order to avoid patent litigations and high compensation.

Key words: patent litigation, litigation subject, patent operation, social network, cluster analysis