Abstract: Apolipoprotein B（apoB） is widely found in various vertebrates and is an important component of lipoprotein, which plays an important role in lipid metabolism. ApoB in fish has similar function to that in mammals, but different subtypes exist, and there are significant differences in amino acid sequence and APOBEC1 editing mechanism between fish and mammals. In this review, the molecular structure, biological function and factors affecting the expression of apoB gene in fish were reviewed, in order to provide a reference for the systematic study on the mechanism of apoB gene regulating lipid metabolism in fish.