The performance of an aircraft wing mostly depend on the aerodynamic characteristics i.e. lift force, drag force, pressure distribution, ratio of lift to drag etc. In this paper the influence of aerodynamic performance on two dimensional NACA 4412 airfoil is investigated. The computational method consist of steady state, incompressible, finite volume method, spalart-allmaras turbulence model. The flow has been studied with the help of Navier-Stroke and continuity equations. Numerical simulations were performing at Reynolds number (1x10 6 , 2x10 6 , 3x10 6 , and 4x10 6 ) at different angle of attack (0 0 , 3 0 ,6 0 , and 9 0 ). The results give the satisfactory measure of confidence of fidelity of the simulation. Aerodynamic forces are calculated with different Reynolds number and angle of attack, after analyzing the data it is found that the higher lift coefficient was obtain in Re-4x10 6 at angle of attack 9 0 whereas low drag coefficient was obtain in Re-1x10 6 at AOA-0 0