A method that combined global positioning system with Beidou navigation satellit e (GPS+BDS) systems for real-time orbit determination is presented. There has been significant improvement in the satellites′ geometric distribution and the accuracy of real-time low earth orbit (LEO) determination. A weighted least square (WLS) based algorithm using the pseudorange observations is developed to estimate position of LEO satellites for the combined systems.No LEO satellite operates with BDS+GPS receivers at present. Hence the combined algorithm is required to be tested and verified by simulati on through GPS/BDS broadcast ephemeris and STK software. Results show that the accuracy of the proposed combined algorithm is improved by over 26% compared with GPS-only algorithms.