Abstract: Taking 1130 soil samples and middle tobacco leaf samples from Yunyan brand Yunnan raw material base in 37 counties of 5 cities, we analyzed the chlorine content characteristics and carried out the zoning study. The results showed that the average chlorine content of middle tobacco leaves was 0.29%. The distribution frequency of chlorine content below 0.3% was as high as 71.33%, and the frequency of sample distribution in 0.3%-0.8% suitable range was only 22.75%. The average chlorine content of soil was 15.37 mg/kg. The highest frequency of sample distribution was <10.0 mg/kg range, accounted for 61.68%. The distribution frequency of 10.0-30.0 mg/kg samples in suitable range was only 28.23%. The highest content of water-soluble chlorine was at the altitude range of 1800-2000 m, and the lowest was <1600 m. The content of water soluble chlorine in the middle loam was the highest, and the content in light clay and medium clay was relatively low. Only 28.23% soil samples and 22.75% tobacco samples were in suitable range in Yunyan brand Yunnan raw material base. 61.68% the soil samples and 71.33% the tobacco samples had lower chlorine content than the suitable range.