8. The land emissivity characteristcs analysis over different geographical distribution Author： Lijuan Shi,Yubao Qiu Affiliation： CEODE The microwave emissivity over land is significant for describing the microwave emission characteristics of the land, different land covers have their own emission behavior, which is related to structure, water content, surface roughness ect.. Emissivity performance of the same land cover in different regional environment should also be different. In this study, the global land surface emissivities have been calculated using six month (the summer time from June,2003 to August,2003 and the winter time from Dec,2003 to Feb,2004) AMSR-E L2A brightness temperature, MODIS land surface temperature and the layered atmosphere temperature, humidity and pressure profiles data retrieved from MODIS/Aqua under clear sky conditions. We analyzed the emissivity changes of the same land cover in diverse regions at continental scale, and discussed time-series variation regularity of this change at monthly scale. In the regional climate change and the land parameters retrieval, the emissivity difference characteristics in different geographical distribution is also critical, thus we evaluate quantitatively the land covers emissivity changes with altitude and latitude using the GTOPO30 DEM data.