Abstract:To further determine the quantitative relationship between the bioconcentration factor (BCF) of rice cadmium (Cd) and influencing factors, this study was carried out based on the routine monitoring data of the southern rice-producing areas provided by the Agro-Environmental Monitoring Center of China. The correlations between soil available Cd content, pH, soil organic matter (SOM), cation exchange capacity (CEC) and rice BCF were systematically analyzed, and the quantitative relationship models were established by multiple linear regression. The results showed that soil total Cd content ranged from 0.25 to 10.34 mg/kg with the average of 1.94 mg/kg, which was 4.85 times of the risk screening value (0.4 mg/kg) for Cd contamination in Soil boironment Quality Risk Control Standard for Soil Contamination of Agriculture Land (GB15618—2018). The results of linear correlation analysis showed that BCF of rice Cd had significant positive correlations with soil available Cd and SOM (P<0.01), the correlation coefficients were 0.395 and 0.474, respectively, while significant negative correlations with soil pH (P<0.01) and CEC (P<0.05), the correlation coefficients were -0.470 and -0.200, respectively. The model constructed by multiple linear regression was lgBCF=-0.346pH + 0.013lgSOM + 0.181lgCdavailable+ 2.001 (R2=0.560, P<0.01, n=112), which can better predict Cd content in rice and the safety threshold of soil Cd in rice production areas in southern China.