The storage proteins of the mulberry longicorn beetle, Apriona germari Hope, were purified and characterized. Three kinds of storage protein (SP1, SP2 and Sp3) were purified from the last instar larval hemolymph of A. germari by the FPLC techniques, anion exchange chromatography and gel permeation chromatography. The SP1, SP2 and SP3 have a native molecular weight of 480, 440 and 420 kDa, respectively. In the SDS-polyacrylamide gel electrophoresis analysis, these storage proteins are composed of a single protein subunit with molecular weight of 90, 85 and 80 kDa, respectively. This result showed that the storage proteins are hexameric protein. The SP1 and SP2 were stained with Schiffs reagent, but SP3 was not stained. It can be assumed that SP1 and SP2 are glycoprotein. Western blot analyses using the each of polyclonal antiserum against purified SP1, SP2 and SP3 showed that the three antibodies reacted with the each of SP bands, respectively. Also, antibodies against SP1 and SP3 cross-reacted with the SP3 and SP1, respectively. However, SP2 was not cross-reacted with these two antibodies. Also, antiserum against SP2 did not cross-reacted with the SP1 and SP3.