中文摘要：

近年来我国证券分析师研究报告的质量备受投资者质疑，本文用事件研究法对2006年1月1日--2010年12月31日期间5998份研究报告的市场反应进行了实证研究．结果表明证券分析师调整股票评级存在复述市场信息的行为，向市场提供的新信息非常有限．投资者据此获得超额收益非常有限。机构投资者等诸多利益冲突因素、我国证券研究部门粗放式的运营模式、证券分析师频繁的流动以及年轻分析师的声誉忧虑等是导致我国证券分析师复述市场，研究报告信息含量和信息质量不高的主要原因，在此基础上．本文从监管当局、行业协会、券商和分析师自身三个层面对相关的监管治理举措进行探讨.

英文摘要：

For the recent years, the quality of security analysts＇ reports is widely questioned by investors. By using an event-study method, this paper carries out an empirical study on market reactions of 5998 research reports with a time-span from Jan 1st, 2006 to Dec 3hh, 2010. The study results imply that the analysts＇ recommendation indeed piggyback the information existed in the market. The piggybacking behavior result in providing limited new information, rely on which, the investors could barely reap excessive returns. The extensive running mode of research department of security firms, frequent turnover of security analysts and career concerns of young security analysts are all the primary causes for security analysts reiterating information and dissatisfactory information quantity and quality. On this basis, this paper discusses on relative supervision and regulation procedure through three aspects such as supervision watchdog, industry association and analysts themselves.