Abstract： Objective To observe the changes of the expression of GnRH mRNA in pancreas of rats in different age, and to analyze the relationship between the mRNA change and the changes of glucose metabolism. MethodsThe rat experiment included three groups: young(1-2m), middle-aged (7-8m), old(14-16m) male rats(each n=7-8).Oral glucose tolerance test (OGTT) was carried out,and real-time quantitative PCR was done. Results (1) the levels of the blood glucose and insulin(60min, 120min) were higher in aged rats than other two groups (all P<0.01).The HOMA-IR, △I30/△G30, △I120/△G120 were higher in aged group than in other two groups (all P<0.01). (2) The aged group had the lower level of the expressions of GnRH mRNA as compared with the other two groups (all P<0.05). (3) There was negative correlation of the levels of the blood glucose and insulin(0min/120min),△I30/△G30、△I120/△G120,HOMA-IR with the expression level of GnRH mRNA. Conclusions In aged rat group, the expression of GnRH mRNA in pancreas is decreased, there are significantly negtive correlations of GnRH mRNA with glucose metabolism abnormalities. The expression change of GnRH mRNA in pancreas may be related to the age-related abnormality of the glucose metabolism.