User innovation is becoming increasingly common and has been playing a more and more important role in the enterprise innovation system . Therefore , a systematic study on the behavioral and evolving conditions of the user innovation is theoretically necessary . The user innovation behaviors are divided into three paradigms : User-centered innovation , User cooperation innovation and User self-innovation , categorized by the extent to which the users are involved and the phases in which the users participate . A model of the conditions and paradigms for user innovation is proposed in this paper . The result of the empirical investigation indicates that several factors that deeply affect the innovation activities include innovation desire , innovation capability , agency cost , complexity of innovation project and information stickiness . Different conditions lead to different innovation paradigms;and innovation behaviors in different phases need different conditions too . Enterprises can choose the favorable innovation style in certain conditions so as to make the best use of the user innovation capability and enhance its market competitiveness .