Abstract: Heavy mental is a kind of non-degradable, highly enriched common water pollutants, which can be accu-mulated in brain, kidney and liver, and other organs of fish. It can produce molecular and physiological and biochemical toxicity to fish, which affects the growth, reproduction and metabolism of fish, and even causes death. The present paper reviewed the influence of heavy metals on fish, from several aspects including heavy metals entering body of the fish, ac-cumulation of heavy metals in fish, acute toxicity of heavy metals to fish and toxicity mechanism of heavy metal to fish. It emphasized that the systematic study on toxicity mechanism of heavy metals in fish should be strengthened in the future. The joint toxicity effect of different kinds of heavy metals on fish was investigated to confirm the influential factors and the dose -effect relationship between exposure concentration of heavy metals and response index. The signal transduction mechanism of oxidative stress of fish under heavy metal stress was also studied. In addition, the study on early warning biomarkers of environmental heavy metal pollution also should be strengthened, and the research of heavy metal toxicity to fish should be combined with online water quality monitoring and early warning, it also needs to screen and domesticate the warning fish and to select fish biology signal sensitivity index, which can provide a scientific basis for fishery environ-ment monitoring and healthy fish breeding.