This experiment was conducted to determine the effects of feeding CLA and coumarin on the changes of biochemical composition of velvet antler and blood serum in spotted deer (Cervus nippon). There were no significant differences between treatments in crude protein, crude fiber, and crude ash contents of velvet antler. The content of fatty acid did not differ between treatments, although there were significant differences (P<0.05) in C16:0 and C20:0. The content of collagen was significantly higher (P<0.05) in control than those in CLA and coumarin treatments. There were no significant differences between treatments in the contents of amino acids. Some constituents of blood showed much differences in comparison of pre and post-experiment for all treatments. Feeding of CLA and coumarin was not influential on the chemical composition of velvet antler and blood serum.