The applications of satellite data are effective methods for solar energy resources assessment. These methods were applied in China from the 1980s at two aspects, one is using satellite remote sensing data directly (Statistical Methods), and the other is using satellite remote sensing data indirectly (Physical Methods). With the summary of these two aspects, the advantages and difficult points of the satellite data application in solar energy resources assessment are discussed. It is considered that the observation method from above to below and the high resolution are the main advantages. However, the calculations of the influences of cloud and aerosol on surface radiation are the two difficulties.