Diapause eggs of Bombyx mandarina Moore from Wujiang, Jiangsu Province, China, were used to study the artificial hatching of B. mandarina Moore. The results showed that the highest hatchability was obtained by instant treatment with hydrochloric acid (HC1, specific gravity 1.065-1.075) for 5 min under 46℃. After the B. mandarina eggs were cold stored at 5 ℃ for 40 days, the highest hatchability was obtained by treatment with HC1 (specific gravity 1.092) for 6 minutes under 47.8 ℃. For the B. mandarina eggs that were stored at 25 ℃ for 28 d and then cold-stored at 5 ℃ for 0-100 days, the highest hatchability was obtained by treatment with HC1 (specific gravity 1.092) for 6 min at 47.8℃. The longer the cold storage period, the higher was the hatchability. Acid treatment on diapause eggs of B. mandarina for 6 mins at 47.8℃ with hydrochloric acid (specific gravity 1.092) before hatching in spring could obviously shorten the hatching stage and increase the hatchability.