This study aims to examine the effect of managerial ability and environment uncertainty  on tax avoidance. The sample in this study is 89 firms that listed in Indonesia Stock Exchange 2011-2015. The sample are selected using purposive random sampling method. Total Firm-year observations in this study is 445 companies. By using OLS regression, we find that managerial ability has negative and significant relationship between tax avoidance and managerial ability. Our results also show that environment uncertainty is positively related to tax avoidance.