In this research we adopted the basic concept of event study, choosing three times of President elections and two times of Taipei and Kaohsiung mayor elections as sample events and taking stock market returns to be the target of analysis. We divided days around event date into two parts, each of them contains event period and estimate period, four time intervals in all. Then, we used several different statistical methods to see if there is election bull runs.In the studies of earlier period the most affirms in domestic election periods that the election bull runs are easily to be happened. While using nonparametric methods or Ordinary Cross-Sectional Method, ANOVA analysis, Time Series regression analysis, we can not get sufficient evidences by this study, there are 3 possible reasons. The first possible reason is the diversification of the financial merchandise provides the investors to obtain another chance of excess profits. The second possible reason is the environmental change of investment in domestic stock market. The third possible reason is that stock market is an economic window, and economy contains more than elections. The proportion of investors in Taiwan Stock Market which consists of foreign investors, Securities Investment Trust Companies and Dealers is increasing and the total of listed companies is up to 693 currently. Numerous merchandises that weed through the old to bring forth the new provide innumerable ways of hedge and speculation. And in this democratic country party alternation is likely to happen again and again. Synthesize the above, one can hardly manipulate the stock market more than in 1980’s and 1990’s. If customers expect that election bull runs will take place in the next elections, we should strongly recommend them to be conservative by the conclusion of this study.In this study we see that some times Taiwan stock market’s performance is divorced from the other international stock markets before party alternation occurs. However, after the party alternation, elections seem not to be the main factor to influence the stock market, performance of Taiwan stock market itself binds the other markets, and the connection goes higher and higher. There is something special in this study we find that Taiwan stock market is relative to Nikkei 225 rather than Dow Jones, although most of the investment institutions take U.S. stock market as a standard when we survey the interaction between Taiwan stock market and the international stock markets. This is a very interesting view in the whole study we assumed that the national conditions, folkway, economy, climate, exportation, domestic demand, politics, etc…., are similar between Taiwan and Japan. So the performances of the two stock markets connect closely.The main purpose of this study is to realize that the results of elections if there are profound influence on stock investment. After the party alternation, we find that the election bull runs do not significantly exist, which differs from the early studies. As a stock market investor, one should treat this result for calmness.