Abstract: As feed raw materials, the crude extracts of Angelica sinensis's yield and their effects on feed and fish are still unclear. Therefore, we explored the effects of fat soluble extract of A. sinensis by-product (FSE) on the growth of fungi in pellet feed and the biochemical indicators in various tissues and organs of carp (Cyprinus carpio var. Jian), in order to provide a theoretical basis for the development of FSE as a functional raw material for fish feed. Firstly, we obtained four polar extracts of A. sinensis by-product by using solvent extraction method, and obtaied FSE by mixing petroleum ether extract (PEE) and ethyl acetate extract (EAE) of A. by-product. Then, we formulated the experimental diets by adding extracts of A. sinensis by-product to the basal diet, and fed the carps with diets containing different levels of FSE. The results show that FSE inhibited the growth of mold in pellet feed significantly while affecting multiple physiological parameters in fish. It decreased the plasma hemoglobin (Hb) levels, tissue hydrogen peroxide (H₂O₂) levels, intestinal malondialdehyde (MDA) levels, and red blood cell methemoglobin (MetHb) levels, while increased the levels of triglycerides (TG) and glucose (GLU), multiple tissue reduced glutathione (GSH) levels, and key enzyme activities, including lactate dehydrogenase (LDH), lipase (LPS), alpha amylase (AMS), Na⁺/K⁺-ATPase, alkaline phosphatase (AKP) and other digestive metabolism related enzymes, as well as antioxidant enzymes such as catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD). The study indicates that FSE exhibits antifungal effects in pellet feed and can improve the digestive, absorption, and respiratory function as well as antioxidant capacity in C. carpio var. Jian.