In this paper the toxication of Zn²⁺ and NH_3-H on hepatopancreasof the shrimp, Penaeus orientalis, was studied, the main results are as follows: 1. In acute Zn²⁺ toxic experiments, when the adult shrimp was exposed toZn²⁺ of 8.4 to 22.43mg/L, the secretory colls were increased and the resorptivecells were decreased. When the adult shrimp was exposed to Zn²⁺ of 31.66 to 63.41mg/L,the number of secretory cells of the hepatic tubule and the secretory vacuolein these cells increased obviously. Parts of hepatic tubule were distroyed and in-jured. 2. In subacute Zn²⁺ toxic experiments, when the adult shrimp exposed to theZn²⁺ of 0.18 to 0.38mg/L,the hepatopencreas seems not remarkably changed.Whenthe shrimp exposed to Zn²⁺ of 0.58 to 0.78mg/L,the increase in the number of thesecretory cells was proportional to the concentration. 3. The effects on the juvenile shrimp that exposed to low concentration ofZn²⁺ were similar to test on the adult exposed to high concentration. 4. In subacute NH_3--N toxic experiments of the adult shrimp carried out for15 days, during the first 7.5 days changes of the hepatopancreas were similar tosubacute Zn²⁺ toxic experiments. Next 7.5 days Changes of the hepatopancreaswere similar to acute Zn²⁺ experiments. As above, no matter whether the shrimp were exposed to test solutions of Zn²⁺ or NH_3--N,their toxication set up increase ofsecretory cells and decrease of resorptive cells in the hepatopancreas. When se-rious toxication parts of the hepatopancreas were distroyed and injured