We successfully extirpated all four hemopoietic organ-wing disc complexes of the fifth instar larvae of Bombyx mori, and found that most of the treated silkworms could still develop into the moths. We investigated the changes of the circulating hemocytes and evaluated the effects of extirpation on the hemopoiesis. The results showed that proliferation of circulating hemocytes was sufficient to allow development of the silkworms which complexes were totally extirpated. We also found that hemopoietic organ-wing disc complexes extirpation might cause a certain hemopoietic compensation of the remainder complexes during early spinning. Exogenous hormones such as $20-{eta}-hydroxyecdysone$ and juvenile hormone analog had a positive effect on hemocytes proliferation.