In this paper, we present an approach based on 2D slices for measuring similarity between 3D models. The key idea is to represent the 3D model by a series of slices along certain directions so that the shape-matching problem between 3D models is transformed into similarity measuring between 2D slices. Here, we have to deal with the following problems: selection of cutting directions, cutting methods, and similarity measuring. To solve these problems, some strategies and rules are proposed. Firstly, a maximum normal distribution method is presented to get three ortho-axes that coincide better with human visual perception mechanism. Secondly, a cutting method is given which can be used to get a series of slices composed of a set of closed polygons. Thirdly, on the basis of 3D shape distribution method presented by Robert et al., we develop a 2D shape distribution method to measure the similarity between the 2D slices. Some experiments are given in this paper to show the validity of this method for 3D model retrieval.