Considering investment as growth and development stimulant, is very important for all countries. Studies on determination of economic growth in various countries imply that private investment is a major factor on economic growth. Empirical studies show that many factors affect private investment, but the most effective variables are not known yet. In this study, we examine most known common variables on private investment in Iran’s economy. In addition, effects of economical-political uncertainties are analyzed. Our sample duration is from 1959 to 2003. We study short term behavior of variables and run long term model with employing of cointegration technique.
