The spatial and temporal variations of aerosols and their relationships with meteorological conditions in Southwest China were studied to understand the aerosol-meteorology interactions. The spatial distribution of aerosols shows a strong ‘basin’ effect with the highest values of Aerosol Optical Thickness at 0.55 µm (AOT, also denoted τ0.55) (>0.70), fine mode AOT (τ0.55-fine) (0.40 ~ 0.67) and coarse mode AOT (τ0.55-coarse) (0.40 ~ 0.54) are all observed in the Sichuan Basin. The temporal variation of seasonal mean τ0.55 shows dissimilar cyclic variations, which is due to the contrary annual cycle trends of seasonal mean τ0.55-coarse (first decrease and then increase) and τ0.55-fine (first increase and then decrease). Both the results obtained from self-organizing map (SOM) model and principle component analysis (PCA) could imply the reasons for different features of the spatial and temporal variations of τ0.55, τ0.55-fine and τ0.55-coarse, and also confirm that their distributions are influenced by complex interactions among different meteorological factors. The seasonal mean τ0.55 during the selected period is positively correlated with air pressure (PRS) and relative humidity (RHU) but negatively correlated with sunshine duration (SSD). The seasonal mean τ0.55-fine is positively correlated with PRS, RHU, average temperature (TEM) and precipitation (PRE). However, the seasonal mean τ0.55-coarse is only negatively correlated with PRE and evaporation (EVP). In particular, the τ0.55-fine increases (decreases) and τ0.55-coarse decreases (increases) with increasing (decreasing) TEM and PRE. This discrepant trend of τ0.55-fine and τ0.55-coarse might account for the weak relationships between τ0.55 and these two meteorological factors.