This study aims to determine the important factors that can affect the capital structure of companies in the construction construction sub-sector on the Indonesia Stock Exchange (IDX). There are 3 (three) important factors that can affect the capital structure, namely: profitability, asset structure, and liquidity. This research uses purposive sampling in the method of determining the sample so that it gets 9 companies which are the samples of this study. Data used in the form of secondary data taken for 6 years in the period 2012-2017. Multiple linear regression as a data analysis technique used. The results obtained from this study are 1) variable profitability has a significant negative effect on the capital structure of the company's construction construction sub-sector on the Indonesia Stock Exchange (IDX); 2) asset structure has a negative and significant effect on the building construction sub-sector of the company on the IDX; and 3) liquidity has a significant negative effect on the capital structure of the company's construction construction sub-sector on the IDX. Keywords: capital structure, profitability, asset structure, liquidity