Introduction: To identify of motivates and barriers to growth is one of the most important issues in the economic growth literature.

Introducing endogenous growth models by Lucas (1988) and Romer (1989) and the development of this theory in the 1990s, making it possible to include economical, political and social variables in economic theories to test them empirically. Corruption is one of the most important variables in the economic development literature and it is mentioned as a barrier to economic growth and versus social capital is known as Stimulus for economic growth.

Methods: In the present study, a conceptive literature review of the relationship between corruption and economic growth, social capital and corruption is studied and the effect of social capital on the economic growth is investigated too. Therefore, by specification of a system of simultaneous equations, fundamental factors affecting corruption, the relation among social capital, economic freedom, economic inequality and government size with corruption and their relationship with economic growth was estimated.

At first, the relationships between variables are depicted in two-dimensional space in R software like as quantiles regressions. Cross section data 2007 and three-stage least square (3SLS) is used for estimation of the simultaneous equations system.

Findings: The corruption has negative effect on economic growth, and social capital has negative effect on economic growth. The latter negative effect implies a positive effect of social capital on economic growth.

Discussion: Accumulation of social capital, economic freedom and growth of the labor force acted as a stimulus to economic growth, and versus the spread of corruption and income inequality has acted as a barrier to economic growth. So governments can adopt policies to reduce social inequality and corruption, and encourage capital accumulation toward the goal of economic growth.