Under the assumption of information asymmetry, we use event study analysis, simultaneous-equation approach and Hausman Test for endogensis to examine the interactions of price, trading volume and bid-ask spreads on the earnings announcement?Prior studies have implicitly assumed that these reactions are unrelated.

It is proved that there exist the pre-earning announcement drift.

Based on the evidence of PEAD in China s stock markets,the paper deeply studies who drives this anomaly,institutional investors or individual investors.

A Empirical Research on Post-Earnings-Announcement Drift Based on Divergent Investor Opinions;

The surplus report is put into practice in many ways.

Used different estimate index, this article inspected the surplus report in time and relations of achievements change of listing companies in 2000-2002, and pointed that, although the supervisor strengthened the power to standard listing companies annual report, but surplus report in time was not be strengthen more, and the tendency was postponement.

Thus,before making investment decisions by taking advantage of the earnings notices,investors are advised to take careful considerations of the choices of the opportunistic disclosure when the management is faced with financial risks;the regulatory authorities should do the same when constituting the relevant provisions on the surplus notice.