A digital watermark is an invisible mark embedded in a three-dimension (3D) mesh model which may be used for a number of different purposes including mesh model authentication, copyright protection and so on. This paper describes a novel method for 3D model watermarking robust to geometric distortions such as rotation, scaling and translation. A transformation of the model to invariant space is proposed prior to watermark embedding. A watermark sequence is embedded in the host with modifying the lengths between the vertices and the centroid of models in the DCT domain based on the quantization technique to achieve the blind watermark extraction. Simulation results indicate the ability of the proposed method to deal with the aforementioned attacks giving very good results.