Abstract: In order to understand the content characteristics of Cd for arable soil in the carbonate rock area of Chongqing,131 soil samples were collected in the carbonate rock area and 162 soil samples were collected as the contrast in the non-carbonate rock area of Nanchuan District in the southern Chongqing, and the concentrations of Cd and pH were analyzed and determined. The pollution status of soil Cd, the potential ecological risk and health risk to adults and children were evaluated by the geostatistical analysis, and potential ecological hazard index and health risk assessment model. Results showed that the average value of Cd in the soil of the carbonate rock area （mean 0.571 mg/kg） was higher than that of the non-carbonate rock area （mean 0.305 mg/kg）. Compared with the Soil Environment Quality Risk Control Standard （GB 15618—2018）, the over-standard rate of 48.1% in the carbonate rock area was higher than the over-standard rate of 29.6% in the non-carbonate rock area, showing a different degree of accumulation. From the spatial distribution, the areas with high Cd values of arable soil were mainly distributed in Shuijiang town, Dongcheng street, Nancheng street and Jinshan town of Nanchuan district, showing the strong to extremely strong potential ecological risk. The health risk assessment results showed that HQ of Cd was less than 1, and the hazard was negligible; the CR was slightly greater than 10^-6, which was acceptable. The non-carcinogenic risk and carcinogenic risk of the three exposure pathways for adults and children in the carbonate rock areas were significantly higher than those in the non-carbonate rock area, and the non-carcinogenic risk and carcinogenic risk in children were higher than those in adults. Oral ingestion was the main route of exposure to Cd in soil.

Key words: carbonate rock areas, soil, cadmium, potential ecological risk assessment, health risk assessment, Southern Chongqing