在2018年10月《中华人民共和国公司法》修订的背景下，股票回购成为市场热点，上市公司进行股票回购的动机值得探讨。本文利用事件研究法和多元回归分析法，对中国A股市场上市公司发布股票回购公告后所带来的市场效应及其影响因素进行实证分析。基于2017年1月1日至2020年12月31日A股市场上107起回购事件，使用WLS方法调整计量模型进行研究。结果发现，股票回购公告在短期内能带来显著为正的市场效应，且上市公司的回购比例、资产负债率、股利支付率、营业收入增长率和账面市值比均对市场效应有影响。本文有助于上市公司对股票回购有更全面的理解，提出监管建议，丰富我国股票回购领域研究。

Under the background of the revision of the Company Law in October 2018, stock repurchase has become a hot issue during capital market, and the motivation of listed companies to conduct stock repurchase is worth exploring. This paper uses the event study method and multiple regression analysis method to analyze the market effect and influencing factors brought by Chinese A-share market listed companies which choose to repurchase their stock. Based on 107 repurchase events in A-share market on January 1, 2017 and December 31, 2020, the Weighted Least Square method adjustment econometric model was used to conduct the research. The results show that in the short run, the announcement of stock repurchase has a remarkable positive market effect. In addition, the repurchase ratio, asset-liability ratio, dividend payout ratio, operating income growth rate and book-to-market ratio of listed companies all have an impact on the market effect. This paper is helpful for listed companies to fully understand stock repurchase, raise supervisory suggestions, and enrich the research on stock repurchase in China.