To study the effects of Aeromonas hydiophila infection on iron metabolism of Megalobrama amblycephala,the iron content of serum and liver was determined by spectrophotometer and Inductive Coupled Plasma Emission Spectrometer,respectively,and expression of the iron metabolism related genes were detected by quantitative real-time PCR at 0,4 h,12 h,24 h,72 h and 120 h after A.hydiophila infection. The results showed that the content of serum iron in the experimental group was significantly descended at 12 h and 24 h after infection (P＜0.05),while the iron content in the liver was increased though not significantly (P＞0.05). After infection,the expression level of hepc,il-6,jak3,stat3 genes increased firstly,and then descended in the liver,but still significantly higher than that in the control. The results indicated that fish reduced the iron serum content in response to bacterial infections. The hepc,il-6,jak3 and stat3 genes may play important roles in both innate immunity and iron metabolism regulation upon bacterial infection.