中文摘要：

对天灾（四川“5．12”地震、青海“4．14”地震）和人祸（西藏“3．14”事件、新疆“7．5”事件）对股价的冲击效应进行了比较研究．结果显示：1）天灾人祸对所在地上市公司股价都造成了显著的负向冲击，短期影响最为显著的是“3．14”事件，长期影响最为显著的是“5．12”地震；2）两次地震对股市的冲击时间分别为19天和8天，两次群体性暴力犯罪事件分别为7天和6天，天灾的冲击时间比人祸长；3）两次地震给股市造成了30％左右的损失，西藏“3．14”事件造成了15％的损失，而“7．5”事件未给股市造成短期损失；4）股价冲击的传递机制表现为传染效应，受灾股票和配对股票齐涨齐跌，投资者追涨杀跌．另外，还得到了其他一些有意义的结论，例如，在第二次同类事件发生后，投资者表现出了一定的学习能力；不管是在天灾还是人祸中，民族团结情绪都有体现，一定层面上说明天灾人皆不欲，人祸更不得人心．

英文摘要：

This paper quantitatively compares the effects of natural disasters and social violence events would have on stock prices. Two natural disasters and two social violence event are selected as samples： Sichuan＂5.12＂ earthquake ; Qinghai ＂4.14＂ earthquake ; Tibet ＂3.14＂ incident; and Xinjiang ＂7.5＂ incident. The results indicate： 1, both natural disasters and social violence event have significant negative impacts on stock prices of the listed companies where the events took place, among which ＂3.14＂ incident had the most signifi- cant effects in the short run while ＂5.12＂ earthquake had the most significant effects in the long run; 2, the impacts of two earthquakes on the prices lasted for 19 days and 8 days respectively and those of the two social violence event lasted for 7 days and 6 days--respectively natural disasters have longer impacts on stock prices than social violence event do ; 3, the two earthquakes brought about 30 % value losses to the stock market, Ti- bet ＂3.14＂ incident brought about 15% losses while the ＂7.5＂ incident brought no value losses; 4, shocks on stock prices had contagious effects. The prices of the affected stocks and their matching stocks went up and down synchronously and investors tended to chase the trends by selling low and buying high. Besides, some other interesting results are drawn from our empirical study e. g. when similar events took place for the second time, the investors showed their learning ability; and no matter in natural disasters or social violence event, nationalism was observed in stock markets where both incidents were not welcomed by investors.