In this research we adopted the basic concept of event study, choosing AMWAY of China 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. This study applied the market model and regression of event study to explore the abnormal return about the AMWAY event of the tourism industry in Taiwan. The empirical period was from August, 26, 2008 to April 6, 2009, including 150 trading days and 11 observations. The result indicated that the positive abnormal return occurred in the tourism industry in Taiwan. The tourism industry in Taiwan was not a semi-strong form efficient market because the abnormal return couldn't response quickly.