Atmospheric gravity wave is an important atmospheric dynamic disturbance widely existing in the Earth's atmosphere.It is of great significance to study its distribution and variations for understanding atmospheric physics,atmospheric structure and atmospheric dynamics.Traditional methods of atmospheric gravity wave detection,such as radar and sounding balloon,have the weaknesses of short detection time and low effective detection altitude.The Global Navigation Satellite System (GNSS) Radio Occultation with the advantages of all-weather,low cost and high accuracy has been widely used in the earth's atmosphere detection and research,which provides new observation data for the study of regional or global gravity wave variation and activity characteristics.In this paper,the occultation data of the first Chinese GNSS radio occultation satellite-Fengyu-3C (FY-3C) are used to obtain the atmospheric temperature profile from August 2014 to December 2016,and then the spatial and temporal distribution of gravity wave parameters is estimated and analyzed for the first time.The results show that the potential energy of gravity wave in winter and summer is stronger than that in spring and autumn due to seasonal convection between the land and the sea.Equatorial convection leads to stronger gravity wave in the equatorial region than in the two polar regions.In summer,gravity wave activity is frequent in the middle and low latitudes of the southern hemisphere,and in winter,gravity waves in the middle and low latitudes of the northern hemisphere are active.With the increase of altitude,the potential energy of gravity wave decreases gradually.In addition,the topography is the main source of gravity waves in the lower atmosphere.