This study aims to prove empirically that sales growth, profitability, asset structure, business risk, financial risk, tax, Firm growth and firm size are determinants of the capital structure decisions of companies incorporated in the LQ45 index on the Indonesia Stock Exchange. The sample was taken using purposive random sampling, and the collected panel data were analyzed using panel data regression. The results showed that the independent variables that had a significant effect on the capital structure proxied by the debt to asset ratio (DAR) were: sales growth, profitability, asset structure, and firm size eywords sales growth, profitability, asset structure, business risk, financial risk, tax magnitude, firm growth, Firm size