Hemolymph proteins and vitellogenin from mulberry longicorn beetle, Apriona germari HOPE, were indentified, and their changed were analyzed during the larval-pupal-adult development and in the newly laid eggs. Thres major hemolymph proteins were observed in the hemolymph during the larval-pupal-adult development and the intensity of their proteins was clearly observed during the pupal stage. From SDS-[olyacrylamide gel electrophoresis analysis, molecular weights of three major hemolymph proteins were approximately 74 kDa, 78kDa and 85kDa. Vitellogenin in A. Germati appeared in the hemolymph of only abult female and is considered to be a product synthersized within 10 days after adult emergence. The molecular weight of vitellogenin was consited of a heavy subunit (165 kDa) and a light subunit (40 kDa).