The impact of corporate strategy decisions on capital structure has attracted researchers and managers for decades, though these decisions have so far yielded complex and uncertain results. While previous studies have focused on the effective effects of a single strategy at one point in time, this study attempts to provide an overview of the impact of strategic decisions on capital structure. According to the hierarchical strategy theory, there are three effective strategies, namely external activity, diversification and integration (integration), at the company level. This study was conducted using the annual data of listed companies in Tehran Stock Exchange during the period 2013-2019. By screening, 152 companies were identified as the sample of the study. Multivariate linear regression based on panel data was used to test the research hypotheses. The results of empirical evidence show that the aforementioned strategies influence the structure of corporate capital simultaneously and independently. Integration and external activity are inversely related to debt ratio, whereas diversification is directly related to debt ratio.