Incremental sheet forming (ISF), based on the ‘layered manufacturing’ principle of rapid prototype manufacturing technology, is an innovative and highly flexible technology for forming complex shaped parts without the need for costly dies. This paper presents a numerical investigation on the influence of forming process parameters by modeling the forming process. ANSYS/LS-DYNA has been used for the simulation. The results of study show that small vertical step size can improve the accuracy of the forming. Moreover, large forming angle can increase plastic strain and the four screwdown point optimization paths is an effective method to increase the accuracy of the formed sheet.