Abstract: In this paper, a study on the dynamic orbit determination for geostationary statellite using two-way pseudorange observations are presented. The satellite observation equation and the method for correcting the observations in term of the two-way pseudorange are given. The simulating calculations are performed by using the observation data set of the four monitor stations in China. The results show that the precision of the orbit improvement and extrapolation using seven days two-way pseudorange observation data set are same as those of five days are, but much better than three days’ data set under the condition of random error in 3 m. Using seven days observation, the precision of the orbit improvement is about 5 m and the radial precision of the orbit predication is about 20 m.