Abstract: In this article, we propose a robust watermarking scheme for three-dimensional triangle meshes. First, we calculate the distance of each vertex in the mesh to the center of the mesh. And we get a sequence of real numbers which are the values of distances. Second, we consider the real number sequence as a digital signal in spatial domain and transform it to a signal in frequency domain using one-dimensional discrete cosine transform (DCT). Third, we embed a watermark into the signal in frequency domain, and then transform it back to a digital signal in spatial domain. This new spatial-domain signal represents the new values of the distances after embedding a watermark. Finally, we modify the coordinates of the vertices making their distances to the mesh center satisfy these new values. Experiments show that this scheme is both simple to implement and fairly robust against common mesh attacks such as mesh simplification, mesh cropping, random noise added to the vertex coordinates etc.