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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 τ 0.55 ) (>0.70), fine-mode AOT (τ 0.55-fine ) (0.40~0.67), and coarse-mode AOT (τ 0.55-coarse ) (0.40~0.54), all observed in the Sichuan Basin. The temporal variation of seasonal mean τ 0.55 shows dissimilar cyclic variations, which is due to the contrary annual cycle trends of seasonal mean τ 0.55-coarse (first decrease and then increase) and τ 0.55-fine (first increase and then decrease). Both the results obtained from self-organizing map (SOM) model and principal component analysis (PCA) could imply the reasons for different features of the spatial and temporal variations of τ 0.55 , τ 0.55-fine , and τ 0.55-coarse , and also confirm that their distributions are influenced by complex interactions among different meteorological factors. The seasonal mean τ 0.55 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 τ 0.55-fine is positively correlated with PRS, RHU, average temperature (TEM), and precipitation (PRE). However, the seasonal mean τ 0.55-coarse is only negatively correlated with PRE and evaporation (EVP). In particular, the τ 0.55-fine increases (decreases) and τ 0.55-coarse decreases (increases) with increasing (decreasing) TEM and PRE. This discrepant trend of τ 0.55-fine and τ 0.55-coarse might account for the weak relationships between τ 0.55 and these two meteorological factors.