Susceptibility of Curculio sikkimensis adults to 39 commercial insecticides were evaluated by body dipping method, Among them sixteen insecticides of chlorpyrifos, fenitrothion, fiponil, phenthoate, benfuracarb, thiodicaib, carbosulfan, bifenthrin, cypermethrin, $lambda$-cyhalothrin, deltamethrin, clothianidin, acetamiprid+diflubenzuron, etofenpox+diazinon, esfenvalerate+fenitrothion and furathiocarb +diflubenzuron showed 100% mortality. Insecticides with over 80% residual effect at 1 day after treatment were phenthoate, benfuracarb and thiodicarb (95.0, 82.5, and 85.0%, respectively). However, after that, it was dropped rapidly. Other insecticides showed low residual effect. In the control efficacy test on C. sikkimensis, insecticides with over 90% control values at 1 day after treatment were phenthoate, thiodicarb, fipronil, acetamiprid+bifenthrin and furathiocarb+diflubenzuron. However, all insecticides from 2 days after treatment were over 90%.