Objective To extract the color feature of tongue image.Methods The tongue image was divided into 8?8 dynamic rectangular grids. Then the color histogram of each grid was calculated. All of them composed a high-dimensional vector (we call it the original feature vector).Finally, the dimensionality of the original feature vector was reduced by using Landmark Isomap. Results Experiments on 3 594 tongue images showed that several color features of tongue image, such as the color of tongue substance, the color of tongue coat, the shades of tongue color, and so on could be extracted. Conclusion This proposed method can be used to extract the color feature of tongue image effectively.