Abstract:The injury process of the chestnut gall wasp,Dryocosmus Kuriphilus Ya sumatso,an important insect pest of chestnut,and its control were investi gated. It was found that killing of the first-instar larvae in the buds just before winter tesulted in normal growth of the buds the following year and that once a year of high-dose spray of monocrotophos between the timve of harvesting and leaf falling killed 75%-95% of the larvae and effectively reduced the injury.This method was safe to the natural enemies and the re sidue of insecticide was near zero.