This paper analyzed the spatio-temporal variations of Aerosol Optical Depth (AOD) over seven provinces in northern China (i. e. Beijing, Tianjin,Hebei,Shandong,Henan,Shanxi and Shaanxi) from March 2001 to February 2017 based on MOD08M3 product,using GIS statistical analysis technology and the Ensemble Empirical Mode Decomposition (EEMD) method. Results showed that: ①In view of spatial features,there was a direct relationship between population density and the spatial distribution of AOD. From one aspect,terrain factors mainly affect the spatial distribution of AOD by affecting population density. From other aspect,the topographic factors can also affect the horizontal diffusion of aerosols,which makes the spatial variation gradient of AOD increase sharply in the junction of the plains and mountains. This explains the highly fit distribution features between the spatial characteristics of AOD and the terrain. Therefore,terrain factor is one of the most important factors affecting the spatial distribution of AOD in northern China. ②In view of temporal features,application of EEMD in the analysis of AOD temporal variations enables the analysis of the change characteristics at different scales from frequency domain. The temporal variations of AOD in northern China were resulted from multiple fluctuation rules superimposed together,including inter-annual variation (IMF5) ,seasonal fluctuation (IMF3) ,human event volatility at 12-month interval (IMF2) ,and emergencies and suddenly happened situations (IMF1) . These results are useful for studying the temporal and spatial variations of AOD and the climatic environment in northern China.