中文摘要：

西方IPO抑价理论大多在信息不对称、委托代理、信号显示等信息经济学框架下，基于资本市场的有效性假设而提出的，即假定二级市场对股票的定价是合理的，IPO抑价是源于发行定价偏低。中国A股市场IPO抑价率长期高企但连年下降，对该问题的研究，不能简单套用西方理论，而必须结合我国证券市场环境及IPO发行审括制度，将制度因素作为内生变量来考察。

英文摘要：

Most of western theories on IPO underpricing are based on Information Economics such as Asymmetric- Information, Agency- Cost, Information Signaling, which suppose that the capital market is efficient and the trading stock price is reasonable and that the abnormal initial returns of IPOs are resulted from the underpricing of offering price. The IPO underpricing of Chinese A- shares market is very high and is decreasing year by year. Studies on this topic should not automatically imput the western theories. The back groundings of Chinese stock market and the unique approval IPO systems should be taken into considerations, and system factors should be taken as an endogenetic variable.