Objective The three-dimensional knee model has been developed to compute the kinetics of patella-femoral joint. Methods The three-dimensional skeletal model, including superior end of tibia, inferior end of femur and patella, has been developed based on CT image processing and CAD technology. In addition, quadriceps has been defined as straight-line model with ligaments and other soft tissues defined as non-linear elastic fiber model. Quadriceps forces were used as input control variable. Results Such an effective model has been built up successfully in this way. Conclusion It is useful for some kinetic parameters in gait of patella-femoral joint to be computed based on this model.