In this paper, using a static Financial Computable General Equilibrium (FCGE) model we investigate the effect of oil export decline on GDP, private consumption, investment, government expenditure and production of different sectors in Iran's economy. Zero profit conditions, market clearance, income balances, flexibility of government expenditures, imperfect mobility of labor across sectors, imperfect substitution of domestic and foreign goods, firms and households maximization based on CES functional forms are our main assumptions to set up the model. We calibrate our model based on Iran's Social Accounting Matrix (SAM) provided by central bank, which presents economic transactions data of 47 activities, 112 goods and services, 7 financial assets and 5 institutions. Our simulations shows that 50 percent reduction in oil export results 6.22, 4.9 and 13.63 percent reduction respectively in the level of GDP, private consumption and government expenditure, while in this scenario non-oil export shows 18.49 percent expansion. We also provide sensitivity analysis to support our findings.