Anew method was used to rerttove heavy metals in sea water.The requirement of nipper in sea water of egg hatching and naupliar metamorphosis of Penaeus chinenris was investigated.A certain amount of nipper ion and chelator nitrilotriacetic acid (NTA) were added in the de-heavy-metal-ionized sea water and then the cupric ion accvity was calculated.The effects of nipper ion on egg hatching and naupliar metamorphosis were observed.It was first found by experiments that trace ionic copper (10-10.08-10-8.80 mol/dm3) was essential to the growth and development of egg and nauplii of penaeid shrimp and chelated nipper had no actions for these living processes, but in high wncentrations (>10-7.00 mol/dm3) ionic nipper was toxic.The naupliii were more sensitive to necessity and toxicity of ionic copper than eggs.