The contents of chlorine in tobacco-planting soils and tobacco leaves, as well as the changes of chlorine content and the residual amount of chlorine in soil were studied by investigation, field experiments and laboratory analysis in Chongqing. The results of investigation indicated that the average content of chlorine in various tobacco-planting soils was 13.4mg/kg with the range of trace to 99.7 mg/kg in Chongqing. The chlorine contents in (90%) of the soil samples were lower than 30 mg/kg, which was very fit for tobacco planting. The chlorine contents in 3.7% of the soils were more than 45 mg/kg and were not fit for tobacco planting according to the Handbook of Tobacco Planting Division. However, the chlorine contents in some soils were less than 2mg/kg that were in 19.2% of the soils in the investigation regions, the chlorine was deficient. The content of chlorine in tobacco leaves was very low, which average content was 0.7 g/kg with the range of 0.11 g/kg to 9.19g/kg in Chongqing. The chlorine contents in 99% of the leaves samples were lower than 3.0 mg/kg, which was the lower limit that demand of high quality tobacco leaves. Compare with the results in 1988, the average content of chlorine in tobacco-planting soils was decreased for 5 mg/kg and in tobacco leaves was reduced for 60.0%. The residual and leach amount of chlorine in soil was affect by the amount and intensity of rainfall.