Abstract: Heavy metal pollution in soils has become an extensive concern of the ecological environment problems in China. Understanding of distribution and source of Cd pollution in soil in karst areas could provide a basis for the assessment and management of soil environmental quality. Here, we collected the soil Cd related research literature, which covers 206 cities (counties) from eight provinces of southern China. We used the single factor pollution index method to evaluate Cd pollution levels and used the Pearson’s correlation analysis to reveal the linkage between the Cd concentrations and the area of exposed carbonate rock, and discussed the source of pollution. The results showed that: (1) The soil in karst areas of southern China had high Cd concentration, with a geometric mean value of 0.36 mg·kg^-1, which was higher than the national average, the world average and the regional average of non-karst areas. (2) The pollution degree in different provinces was in order of Guangxi > Hunan > Sichuan > Guangdong > Guizhou > Chongqing > Yunnan > Hubei. (3) Anthropogenic activities including mining, urbanization, and agricultural activities were not the main reasons for high soil Cd concentrations in karst areas of southern China. The high background value of Cd in carbonate rocks and the relative enrichment of Cd in weathered carbonate rocks were the main natural factors for high Cd concentrations in karst areas of southern China.

Key words: succession, soil aggregate, Changbai Mountain, broad-leaved Korean pine forest, organic carbon.