This study uses Taiwan-listed and over-the-counter companies from 2010 to 2016 as the research data; effective tax rates and book-tax difference as proxy variables for tax planning to explore the relationship between the top management team power , the company's supervision mechanism and tax planning. Related research finds that top management have self-interested behavior. However, the empirical results of this study found that the greater the power of the top management team, the lower the degree of corporate tax planning. The research results also found that the power of the top management team is negatively correlated with the extent to which the company engages in tax planning, with the size of the company's board and whether it is audited by a large cpa firm as moderating variables. However, the higher the shareholding ratio of institutional shareholders, the more the enterprise will conduct more tax planning activities. The results of this research will fill the gap in the research on the power of the top management team in firm's tax planning.