the countries of the world are using various communication services in all areas of society on based satellite networks. The International Telecommunication Union has allocated two kind of satellite position in space segment to Mongolia that are 113.6E longitude for Fixed Satellite Service-(FSS) and 74E longitude for Broadband Satellite Service-(BSS).Mongolia is planning to launch its national satellite in 2030. Therefore, there are studying many kind of science research including estimate satellite geometry parameters, rain attenuation, cloud attenuation and satellite network architecture based on national satellite that will be launched to space segment.This paper is described by detail that is the mathematical modelling of satellite geometry parameters particularly antenna look angles of the ground control station.In this paper, aim of research work is determined the geometrical parameters of the national satellite 113.E and 74E to be launched in Mongolia by using a mathematical model to make a comparative analysis and to show some result.