The pattrens and concentration of hemolymph protein in the chestnut weevil, Curculio dentipes (Roelofs) according to development stages were determined by SDS-polyacrylamide gel electrophoresis and spectrophotometric method. The protein contents were found to be the maximum at the nonoverwintering larva and decreased at the wintering larva and the overwintering larva and then reached minimum level at pupa stages. The denatured proteins were separated into 44 bands between the highest M.W. 230,200 daltons and lowest M.W. 15,900 daltons during all stages. The band of M.W. 77,900 daltons appeared during all stages and showed greatest color density. Particulary, at overwintering larva and pupal stages, large variation were observed in protein bands.