Cysts of Brine shrimp (Artemia salina) were collected from three different places in China, from Chengkou Salterns of Shandong, Yinggehai Salterns of Hainan Island and Salt Lake of Qinhai, The chorion thickness of he cysts of the three strains were 9.7μm, 11.4 μm and 13.2μm respectively. The highest hatchabilities were obtained by incubating the cysts in freshwater for 2,3 and 4 hours respectively before hatching in sea water. The optimal hatching temperature were 25.5-28.5°, 27.0-30.0° and 27.0-33.0℃ with the optimal salinities 30, 20 and 35‰, the hatching period were 6.5, 6.4 and 7.4 hours separately.The cysts were collected in 24 hours after production and cultured under laboratory condition. The effects of different deactivation treatments on the hatchability were studies. The most effective treatments were as follows:1. For the chengkou cysts, the hatchability of 91—94% was achieved by soaking the cysts in saturated crude salt solution for 2—3 months.2. For the Yinggehai cysts, the hatchability of 80—90% was achieved by soaking the cysts in saturated crude solution for 2—5 months.3. For the Salt Lake cysts, the hatchability of 96—98% was achieved after pre-incubation the cysts in 11° Bé brine at 5℃ for 2—3 months.However, the newly produced cysts could not be activated by soaking in 3% H₂O₂ or formaldehyde solution. Moreover, the hatchability of the cysts collected naturally can be increased by soaking in 3% H₂O₂, 3% formaldehyde, or decapsulation treatment.