Abstract: Political participation is the important part of the democratic construction.On the basis of whether it conforms to the legal system stipulation related procedure,political participation can be divided into two types: the institutional political participation and non-institutional political participation.The trend of non-institutional political participation is upward at present in china,and becomes a prominent problem.It is of great significance for the development of democracy and the construction of harmonious society to analyze the reasons and bring forward a reasonable way out.This article,taking Xiamen PX event for example,attempts to analyze the factors causing the non-institutional political participation,from the angles of national system,culture and information technology.