This study aims the influence of stock split announcement on stock liquidity and stock return for determining the differences on Trading Volume Activity and abnormal return before and after the announcement of stock split. The stock liquidity in this study can be known through the Trading Volume Activity, whereas the stock return can be known trough the abnormal return. A type of research used in this study is a quantitative approach by using event study. The criteria for sampling used is purposive sampling, in accordance with prefetermined criteria that there are 32 companies sample. The result showed that there is a market reaction around the announcement of a stock split. However, there is no significant differences Trading Volume Activity and abnormal return before and after the announcement of a stock split. With regard to the research result, there is a positive reaction around the stock split announcement. The result research showed that investors are less interested in the shares offered, that Trading Volume Activity does not increase, then there is no an increase in liquidity. Furthermore, investors cannot enjoy the abnormal return over the longer term.