The research aims at analyzing the factors asset structure,firmsize,growth, and profitability that influence the capitalstructure on companies listed on the Jakarta Islamic Index (JII) for the period of 2011-2014. The factors analyzed are asset structure, size,growth, and return on assets (ROA). The samples are taken using purposive sampling method with as many as 19 companies as the samples of the research. The analysis of the research is done using Multiple Linier Regression. The result of the research indicate that factors, asset structure,firmsize,growth, and return on assets (ROA), simultaneously have significant influence on the capitalstructure. Partially,asset structure,firmsize, andgrowth variables havenot effect on the return of capital structure. Return On Assets (ROA) variables do a significant affect the capitalstructure. Whereas, Return On Assets (ROA) variable has a dominant influence to affect the capitalstructure.