Abstract: We investigated the effects of copper on the growth and survival of juvenile loach (Misqurnus mizolepis) in flow-through or renewal test with a hardness of 115 mg/L(as CaCO3). tests began using newly hatched loach larvae and were run for 30 days in flow-through test or 16 days in renewal test. The results showed that, in flow-through test, the lowest observed effect concentration (LOEC)for copper, at which significant effects on the survival of the loach were observed, was 41.2μg/L, and the no observed effect concentration(NOEC)was 25.2μg/L. In renewal test, the NOEC and LOEC for copper were 19 and 38μg/L respectively, based on the standing crop.