A new method for ergonomic design of a computer mouse is proposed in this paper.In the method,the movements of joints and tip of the forefinger during operating a mouse was captured by a high-speed video camera.The captured videos were analyzed and an algorithm was developed to decide the size and location of the mouse wheel according to ergonomic principles.The algorithm was then coded in a software package with Visual C++ and OpenGL languages.Results of the calculation and simulation agreed well with those of the experiments.The software can also be used for shape design of mouse body,buttons and their layouts. A new method for ergonomic design of a computer mouse is proposed in this paper.In the method, the movements of joints and tip of the forefinger during operating a mouse was captured by a high-speed video camera. Captured videos were analyzed and an algorithm was developed to decide the size and location of the mouse wheel according to ergonomic principles. algorithm was then coded in a software package with Visual C ++ and OpenGL languages. Results of the calculation and simulation agreed well with those of the experiments. software can also be used for shape design of mouse body, buttons and their layouts.