The aerodynamic performance of modified NACA64-418 with irregular blunt trailing edge shape has been investigated. In order to reduce the drag of blunt trailing edge airfoil, the several shapes of trailing edge are tested. The numerical results show that the drag of protruding shape is much more decreasing than that of retreating shape but the lift is almost same values regardless of shapes. Also, the drag around modified NACA64-418 with protruding round trailing edge is increased when the upstream velocity(U<SUB>∞</SUB> ) is increased.