) hepatocyte steatosis and investigate a possible mechanism for lipid emulsion (LE)-induced steatosis in grass carp hepatocytes, normal grass carp hepatocytes were cultured in different inducing media supplemented with different concentrations of LE or fetal bovine serum (FBS). LE and FBS were tested to identify the best medium and optimal concentration. Grass carp hepatocytes were cultured in inducing medium containing 20% or 50% FBS, or different concentrations (0.5–2 mL/L) of clinical vein nutrition drug (20% LE) for 48 h. Lipid accumulation was observed by phase-contrast microscopy, the ultrastructure of fatty degeneration of hepatocytes was observed by transmission electron microscope, the triglyceride (TG) content was determined by Oil red O extraction, the activity of ALT and ASL enzyme were examined biochemically, and the expression of the lipid metabolism genes was determined by real-time PCR. The results revealed that a model of grass carp hepatocyte steatosis can be established using induction medium containing 1–2 mL/L LE, or 20% FBS. The TG level was greatly increased in cells treated with 1–2 mL/L LE, and 20% or 50% FBS compared with that of the control cells (<0.05). However, there was no significant difference in the aminotransferase activity between cells treated with 20% FBS and cells treated with various concentrations of LE(>0.05). In the model of grass carp hepatocyte steatosis, expression of gene expression decreased sharply <0.05). In conclusion, our grass carp hepatocyte steatosis model was established over a short time using 1–2 mL/L LE or 20% FBS. Lipid accumulation in hepatocytes was closely related to the expression of lipid metabolism genes). This study provides the foundations for developing an animal model to explore nutrient metabolism in fish liver, and also provides an alternative way to uncover the mechanism(s) underlying metabolic diseases involving lipids.