Mucor sp.JX23 fermentation broth was used as catalyst for synthesizing acetophenone from cinnamic acid.The effects of the concentration of cinnamic acid,reaction pH value,reaction temperature and reaction time on the conversion of cinnamic acid were investigated.The reaction product was qualitatively analyzed by GC-MS and quantitatively analyzed by HPLC.The results showed that the reaction catalyzed by Mucor sp.JX23 was characterized with a high conversion rate and selectivity.When cinnamic acid concentration was 5.0 g/L,pH = 6.0,reaction temperature was 28-30℃ and reacting time was 2d,the conversion of cinnamic acid was 89.2%,the yield of acetophenone was 3.1 g/L,and acetophenone was the only reaction product.