Abstract: In order to analyze the spatial distribution law of surface water quality in dry season in China and identify its spatial pattern, based on the fusion data of surface water monitoring sections of 31 provinces in dry season (from January to February, 2021, excluding the data of Hong Kong, Macao and Taiwan, the same below), the methods of spatial autocorrelation, spatial clustering and hot spot analysis are used. The results showed that: (1) The spatial distribution of surface water quality in dry season in China shows the asymmetric distribution characteristics of class Ⅰ and class Ⅱ water bodies in the West and central regions, and class Ⅲ and class Ⅳ water bodies in the East and northeast regions. Spatially, it shows a significant positive high aggregation pattern, which is roughly divided into two areas: heavy pollution area and light pollution area, which are divided by the long strip area (i.e. Central Fujian Province-Northern Jiangxi Province-Hubei Province-Shaanxi Province) where the insignificant section in the high/low clustering and hot spot analysis. (2) The location of the boundary line formed by taking the water quality excellent Ⅲ ratio of 0.9 as the standard is basically consistent with the boundary of polluted areas, which proves the accuracy of the identification results of surface water polluted areas in dry season in China. (3) The degree of water pollution in heavy pollution area is statistically significantly higher than that in light pollution area (P<0.05 in the two-sample T test). The correlation between the water quality indicators of the sections in the two regions (0.83 and 0.47) is significantly higher than the correlation of the water quality indicators of the sections between the two regions (0.45). The research shows that the surface water quality in dry season in China has significant high aggregation characteristics, which is closely related to the distribution of surface water resources and the discharge of pollutants.