Aimed at the problem that some visual perceptual degradation and distortion are usually generated during 3D mesh simplification process,we take the salient information as the property of the vertex and partition the bounding box of the mesh into some 3D local window.Then the mean perceptual structural degradation(MPSD) metric based on salient information and information theory is presented and used as a quantitative and objective metric to evaluate the visual perceptual degradation.Both analytical and experimental results show that the MPSD metric can effectively evaluate the visual perceptual structural degradation induced by mesh simplification operations and provide the functionality of multi-scale visual perceptual degradation.