中文摘要：

笔者以2001年～2009年A股上市公司10261个年度观察值为研究样本，研究了信息环境变革和法律制度差异对投资者利益保护的影响。研究结果表明，2007年我国信息环境发生重大变革后，股票市场的知情交易概率显著下降，上市公司注册地法律制度更加完善的地区，该公司股票的知情交易概率更低，信息环境与法律制度对股票知情交易概率具有交互效应。

英文摘要：

The author used the 10261 annual observations of the A -share listed companies in Chinese stock market from 2001 to 2009 as the research samples to study the influence of information environment transformation and legal system variance on the protection of investors＇ benefits. The research results show that after the information environment transformation in 2007, the probability of informed trading in the stock market becomes low. In the areas where legal system is more thorough, the probability of informed trading in the listed company is lower. The information environment and legal system have interactive effect on the probability of informed tradihg of shares.