A single-antenna DGPS aiding attitude determination method was designed. A trackin-differentiator based on integral ap-proximation was constructed. Using the TD, the DGPS velocity data could be filtered to better precise velocity and be differed toprecise acceleration. By analyzing the kinetic model of body and establishing the mathematic model, the solution procedure of atti-tude determination using the velocity and acceleration of body was presented. In the end, the process of simulation of the solutionand the error of attitude curves in the simulation system were presented. Simulation results and relative conclusion were provided.The results show that the method provides a useful source of attitude information and consequently may be used as a backup atti-tude system in vehicle navigation.