Objective: To study the changes in the residues of paeoniflorin and sulfur dioxide in Paeoniae Radix Alba after storage for one year

in order to provide the scientific basis for solving the sulfur fumigation problem in guaranteeing the quality and safety of herbal medicine paeoniflorin. Method: The residues of sulfur dioxide and paeoniflorin in Paeoniae Radix Alba and samples suffocated by sulfur after storage for one year under the same conditions were determined. Result: The contents of paeoniflorin in Paeoniae Radix Alba decreased significantly after being fumigated by sulfur and in the process of being sliced and decocted. The minimum content of paeoniflorin in the prepared slices of paeoniae Radix Alba was 2.805%

which was consistent with the requirement in Chinese Pharmacopoeia for no less than 1.6%. Sulfur dioxide residues were detected

with the maximum residue of 284.239 mg·kg-1 in fumigated samples

which however was still lower than the requirement for no less than 400 mg·kg-1 of sulfur dioxide residue

and would mostly lost during slicing

decoction and storage. Conclusion: Content of Paeoniflorin in Paeoniae Radix Alba decreased significantly after being fumigated by sulfur. Sulfur dioxide residues greatly reduced during softening

slicing and decoction

suggesting that the sulfur fumigation technique could be reserved at present.