This study examines the determinants of capital structure. The research object used is companies in the property and real estate sub-sectors listed on the Indonesia Stock Exchange (IDX) in the 2015-2017 observation year. With a purposive sampling method, which selects samples based on certain criteria. And selected a sample of 42 companies.  Data analysis uses multiple regression and moderated regression analysis (MRA). The results showed that the firm size and profitability had a significant effect on the capital structure while the asset structure variable had no effect on the capital structure. The study implications can be used by management and investors to determine the capital structure through company size and profitability.