Abstract: OBJECTIVE To study the effect on chemical constituents of Codonopsis Radix fumigated in different sulfur dosages and stored at different time, so as to provide reference for the processing and quality evaluation of Codonopsis Radix pieces. METHODS UV and HPLC methods were used to determine polysaccharide, 5-hydroxymethylfurfural and lobetyolin of Codonopsis Radix after being fumigated in different sulfur dosages and storing for 12 months. RESULTS Sulfur fumigation had little influence on the polysaccharides, and had great influence on the 5-hydroxymethylfurfural and lobetyolin. After 12 months, the content of polysaccharide decreased by 5.83%, the content of 5-hydroxymethylfurfural increased by 83.27% and the content of lobetyolin decreased by 54.09%. CONCLUSION Sulfur fumigation has a significant effect on the chemical constituents of Codonopsis Radix. It should be strictly control the use of sulfur in the processing of Chinese medicinal herbs, so as to ensure the quality of Chinese medicinal herbs.