Dietary protein from fermented cottonseed meal (FCSM), widely used in poultry diets in China, had regulating effects on lipid metabolism. To understand the effects of FCSM on the lipid metabolism in broilers, we analyzed the biochemical indexes, enzyme activity, hormone level and metabolites in serum responses to FCSM intake. One hundred and eighty 21-d-old Chinese yellow feathered broilers (536.07±4.43 g) were randomly divided into 3 groups with 6 replicates and 3 diets with 6 % supplementation of unfermented CSM (control group), FCSM by C. Tropicalis (Ct CSM) or C. tropicalis plus S. Cerevisae (Ct-Sc CSM). Result showed that: (1) FCSM intake decreased significantly the content of triglyceride (TAG), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) (P<0.05) in serum; (2) FCSM intake could significantly increase enzyme activity of acetyl CoA carboxylase (ACC), lipoprotein lipase (LPL), fatty acid synthase (FAS) and hormone sensitive lipase (HSL) (P<0.05); (3) Ct-Sc CSM intake increased significantly the levels of adiponectin (ADP) (P<0.05); (4) FCSM intake caused significant metabolic changes involving glycolysis, TCA cycle, synthesis of fatty acid and glycogen, and metabolism of glycerolipid, vitamins B group and amino acids. Our results strongly suggested that FCSM intake could significantly affect lipid metabolism via multiple pathways. These finding provided new essential information about effect of FCSM on broilers and demonstrated the great potential of nutrimetabolomics, through which to research complex nutrients included in animal diet.