The aquatic environment quality of Liaohe River protection area was diagnosed and evaluated by the aquatic comprehensive index and biological toxicity test. The results showed that the survival rates of adult and juvenile zebrafish and the hatching rate of eggs were all more than 50%, suggesting that the biological toxicity of water by acute and chronic toxicity tests was low. Furthermore, there were significant negative correlation relationships between pH, COD, BOD₅ and the survival rates of adult and juvenile zebrafish or the hatching rate of eggs (P<0.05). Therefore, the pH, COD, and BOD₅ had great effects on the development of adult and juvenile zebrafish and eggs. The aquatic quality comprehensive index showed that Yitong River reached grade V and the other rivers reached grade IV of China’s National Water Quality Standards.