A method of computerized tongue image analysis based on image processing for the purpose of digitizing the tongue properties in traditional chinese medical diagnosis is presented. The chromatic information and 2D Gabor wavelet transformation are applied to segment tongue from original image. The statistics method is used to identify the colors of each pixel, which belongs to the tongue substance and coating respectively. Thickness of tongue coating is determined by 2D Gabor wavelet transform coefficient energy (GWTE). The distribution of GWTE and invariant moment algorithm are used to judge the tongue venation. The experiment result shows that methods proposed are effective.