Abstract: This paper presents an approach to 2D polygon deformation based on interactive polygonal shape control,which provides users with timely feedback and deforms the polygon according to the path of users operation to constrained points.The user specifies constrained points on the source polygon,and changes the location of some constrained points.The Changed constrained points have to be at the position specified by the user,while the unchanged constrained points have to maintain the original position.The approach constructs the cost function under the constrains to get the goal polygon,gives real-time feedback after the users operation ,and drive the polygon changing under the interactive control of the user.This method maintains the original relationship between the edge vectors on the polygon,achieves satisfied deformation effects,and avoids the occurrence of unwanted deformation.