Independent director system is a vital tool for improving corporate governance. It plays an important role in the course of corporate governance in Europe and America. This system has been introduced to the listed companies in China ten years, but its proper role does not play well. There have been endless debates on its merits and demerits. Unlike the previous researches, the author of this article tries to study on the behaviors of the independent directors from the perspective of the logic of collective action in economics, and to read the influence that the behaviors of independent directors have on the treating effect.