Capital structure decisions are related to the determination of a certain proportion of the total capital needed by the company to be funded with debt and equity. The purpose of this study is to analyze the effect of profitability, company size, company age, asset structure, business risk and tax rates both partially and simultaneously on the capital structure and firm value. Besides, researchers also tried to analyze the effect of capital structure as an intervening variable on firm value. This type of research is quantitative research. The research sample was selected using a purposive sampling method where 34 companies met the criteria. The method used to obtain data is by library study methods and documentation. The results showed that the variables of profitability, company size, company age, asset structure, business risk and tax rate together had a positive and significant effect on both the capital structure variable and company value. Based on the results of partial hypothesis testing for substructure I conducted through the t-test, indicating that the profitability variable has a negative and significant effect on the capital structure; company size, asset structure and tax rate have a positive and significant effect on capital structure; company age and business risk have no significant effect on capital structure. Based on the results of hypothesis testing for substructure II partially carried out through the t-test, indicating that the variable profitability, company size and tax rate have a positive and significant effect on firm value; asset structure, company age and business risk have no significant effect on firm value. The effect of variable profitability and firm size on firm value through the capital structure as an intervening variable has a non-significant path coefficient value, so the capital structure has not been able to mediate these two variables on firm value. The influence of asset structure variables and tax rates on firm value through the capital structure as an intervening variable has a significant path coefficient so that the capital structure can mediate these two variables on firm value.