Abstract:This paper focuses on the geometrical properties of Inter-Satellite Links (ISLs) of the small satellites formation flying under the elliptical orbits, including the azimuth, elevation and the distance. The article addresses the mathematical formula for these characteristics., and then presents the simulation results based on the given example. The paper also analyzes the law that the formation flying’s ISL’s geometrical characteristics change with the parameters of the satellite constellation. These results are important for future’s constellation design , satellite networking, etc.