Abstract: Spatial distribution and number of GNSS reflection events is one of evaluation standard in spaceborne GNSS-R, and BeiDou system is developed by China independently, whose spatial distribution and number of reflection events is distinct with other navigation system. To analyze above-mentioned distinction, in this paper the complete BeiDou Navigation Satellite System constellation was simulated based on its space segment parameters. BeiDou reflection events spatial distribution calculation procedure was given through the specular reflection point visibility judgment. Its effects on the number and spatial distribution were studied including the orbit height, inclination, argument of perigee and right ascension of ascending node. And BeiDou satellites such as GEO (Geostationary Earth Orbit), IGSO (Inclined Geosynchronous Satellite Orbit) and MEO (Middle Erath Orbit) could provide different reflection events. Simulation results show that the orbit height and right ascension of ascending node affect only the events number, however, the inclination affect both the number and distribution in latitude or longitude, and the argument of perigee has no any influence on the events. The final conclusion was given on the low earth orbit parameters design with the different requirements for the earth observation.