Effects of pH on iontransporting enzyme activities (total ATPase, Na⁺-K⁺-ATPase, V-ATPase and HCO₃^{--ATPase) and survival, growth of Marsupenaeus japonicus postlarvae were investigated. It suggested the osmoregulatory adaptable parameter of postlarvae in pH changing in view of osmotic physiological mechanism and provided the scientific basis of regulation for shrimp aquacultural systems. The results showed that the activities of ATPase, Na+-K+-ATPase, V-ATPase, and HCO₃--ATPase were obviously affected by pH variation（7.1、7.6←8.1→8.6、9.1）, which also had significant effect on its survival rate and weight gain (F＞F_0.05). Within 72 h of pH changing, the activities of ATPase, Na+-K+-ATPase in each treatment group showed peak change with the sampling time, reached theirs climax at 24 h, and stabilized after 72 h, the ATPase activity showed negative correlation with pH, while the activities of Na+-K+-ATPase came back to the level of the control group; meanwhile the activities of V-ATPase、HCO₃--ATPase of postlarvae changed increasingly within 24 h and stabilized afterwards, the activities of V-ATPase and HCO₃--ATPase showed negative relation with pH. In the range of experimental grads, the treatment of pH 7.6, 8.6 had no obvious difference with control ones in postlarvae survival rate, and the treatment of pH 8.6 also showed similar condition with the control group in weight gain. It suggested that the changing scope of pH in Marsupenaeus japonicus postlarvae culturing should not over 0.5.}