Trade war between the United States and China begins when both countries implementing tariffs on imports of products starting in 2017. This study aims to investigate effect of the policy on shareholder prosperity (using variable abnormal returns) and stock liquidity (using variable volume trading activity) in Indonesia Stock Exchange. Data analysis method are using descriptive statistics, normality test and paired sample t-test. The results of this study indicate that export-import tariffs policy of the United States and China on 6 July 2018 do not have significant differences on return and the average trading volume. This indicates that the policy does not contain any information to influence investor decisions in Indonesia Stock Exchange.