In case where strong a priori knowledge about the object being analyzed is available, it can be embedded into the formulation of the snake model. When prior knowledge of shape is available for a specific application, information concerning the shape of the desired objects can be incorporated into the formulation of the snake model as an active contour model. This active contour model can have more robust tracking performance for the weak edge cases because the snaxels of active contour model on weak edges can estimate the likelihood from a priori knowledge about target’s shape and the relations with neighbor snaxels. In this paper we show Five points algorithm can be applied to design invariant energy and the effectiveness of the snake designed on this new concept in robuster tracking for moving object in visual space than the standard snake.