Objective:To examine the transporter 3(ZnT-3) mRNA expression in retina of rats responding to dietary zinc when the dietary zinc is low,and to investigate whether zinc deficient will lead to ZnT-3 expression change at a transcriptional level. Methods:thirty-six male SD rats(4 weeks old) were randomly divided into three groups, the first group(n = 12) was fed for 2 weeks,the second group(n = 12)for 4 weeks and the third(n = 12) for 6 weeks. Then the each group randomly divided into two subgroups,one subgroup(blank control group) given with normal zinc content diet and the other(experimental group) given with low zinc content diet. The third experimental group rats were changed into the diet with normal zinc content from the 4th week to the 6th week. The expression of ZnT-3,carbonic anhydrase 2(CA2) and 14(CA14) were detected by RT-PCR respectively. Results:After the rats took low zinc content diet for 2 weeks,their retina CA2 and CA14 mRNA levels were decreased,and the ZnT-3 mRNA was increased compared with the control; After given the low zinc content diet for 4 weeks,all of the ZnT-3,CA2 and CA14 mRNA levels decreased significantly; Then after being changed back to the normal diet for 2 weeks,the third experimental group rats has ZnT-3,CA2 and CA14 mRNA levels recovery in retina. Conclusion:The result provided evidence that in a zinc deficient animal model,ZnT-3,CA2 and CA14 expression was responsive to zinc at a transcriptional level in retina. To maintain the normal zinc content,the ZnT-3 mRNA expression was regulated by the time and severity of zinc deficiency in rats.