Abstract: By 6% PAGE, it was found that there were two kinds of diapause-associated proteins (DAP)（pI 5.3，4.7） in the hemolymph of diapausing larvae from Henan population and one kind of DAP（pI 4.7） in the hemolymph of diapausing larvae from Shanghai population of Ostrinia furnacalis. The DAPs of O. furnacalis from Henan population were found only in the hemolymph of diapausing larvae. Although the DAP of O. furnacalis from Shanghai population was found in the hemolymphs of both non-diapausing and diapausing larvae, it had higher titer in diapausing larvae. By means of 30%～50% acetone fractionation，Sephadex G-100 gel filtration chromatography and MONOQ RH 5/5 FPLC, the high pure DAP (≥98%) from the hemolymph of larvae from Shanghai population was isolated.

Key words: isolation and purification, diapauseassociated proteins, Ostrinia furnacalis