The experimental result shows that board chairman turnover transmit adverse information to capital market and further study also confirms that earnings quality decline always accompany board chairman turnover that means board chairman turnover is an important opportunity to manipulating earnings,which can be identified by market,inducing significant negative cumulate abnormal returns.

In order to reform the state-owned enterprise with the Shareholding system, based on share-issuing enterprise?s theory and China s actual conditions, we must forge a new management structure sensibly after the state-owned enterprise s reforming, especially a sensible operational mode of board chairman, and make it function in order to promote shareholding system.

The results of these two methods are similar and complement each other,from which we can find that four factors,such as tobin s Q,age,degree and stock turnover,are affecting board chairman and CEO s tenure risk similarly because that both board chairman and CEO are sh.

This article expounds the background of CEO emergence, emphatically analyzes the difference not only between CEO and manager but also between CEO and chairman of board, furthermor.