Abstract: To provide the basis for making a scientific and reasonable processing regulations of Codonopsis Radix, the influence of smoked sulfur on the quality of the Codonopsis Radix was studied. Sulfur dioxide residues was determined by method of distillation, medicinal character was investigated with reference to the description in pharmacopoeia, polysaccharide content was measured by ultraviolet spectrophotometry, content of Lobetyolin and Aractylenolide Ⅲ were measured by HPLC. Finger-print of Codonopsis Radix was established by HPLC. The results showed that the amount of sulfur dioxide residues increased with the time of the smoked sulfur. The higher the amount of sulfur dioxide residues, the whiter the color of Codonopsis Radix and the more obvious the sour of Codonopsis Radix. The content of extract and polysaccharide in apple were increased at different extent after the smoked sulfur, while content of Lobetyolin and Aractylenolide Ⅲ were decreased at different extent, but they had no linear relationship to the amount of sulfur dioxide residues. The analysis of the fingerprint analysis was consistent with the variation of the components content. It can be moderately smoked sulfur in processing and storage of Codonopsis Radix, but the smoked time and amount of sulfur dioxide residues should be strictly controlled. The best smoked time for the fresh Codonopsis Radix should be controlled within 30 min.