economy. In order to simulate this shock, the global trade analysis project (GTAP) model with its data done by using. In the new created data aggregation, oil exporting in Iran and the rest of the world countries as economic new regions, ten new economic sectors have been created, among which the oil is introduced as one sector as well as five endowments. The standard economic closure was changed, and decline in world oil price was simulated in model as a policy shock. The results show that oil export revenue and the mineral commodity export earnings will decrease, but other production sectors’ exports will increase. The trade balance of Iran will be affected negatively and strongly. Also, oil and other services production decreased. In the production sectors’ market, the demand for labor, natural resources, and investment decreased dramatically, and the demand for land increased. Using equivalent variation (EV), changes in Iran’s welfare is high negative. Finally, deflation, reduction in value and quantity of GDP and changes in consumption combination from public to private sector are the other economic impacts of reduction in oil price on Iran’s economic. It is suggested that future studies are done using dynamic models and up-to-date data. In addition, policy makers need to rebound internationally and within OPEC to raise oil prices.