In this paper, A thinning algorithm which can solve a noise problem os proposed. The proposed method is based on the pavlidis thinning algorithm. During a contour tracing period of the given image, the masks of $3{ imes}3$ pixels are proposed. They check all possible caseds of the noise conditions. As soon as the contour tracing is finished, the candidates of the noise are automatically deleted. As a result of the implementation of the proposed algorithm, the similar results which is obtained by noise-free image are obtained and they show the simplified structures comparing with the thinning results of the noisy images. Thus, They illustrate that a simple recognition part is needed to identify the objects.