Abstract：RungeKutta method was introduced to GLONASS orbit simulation to analyze how the step length parameter effects on simulated results，the efficiency of RungeKutta method and the difference between simulated results and broadcast orbit.The result shows that step the balance between algorithm efficiency and accuracy can be keeped though setting step length as 1 s-300 s.The difference between simulated results and broadcast ephemeris increases with time，and reaches about 250m in X，Y，Z directions for 300 minutes simulation time duration.It takes 2 ms to simulate 1 epoch 24 satellites orbit data.According the research，RungeKutta method can be used for GLONASS orbit simulation.
