Objective:To investigate the expression of Insulin/FoxO1/Pdx1/MafA genes during pancreatic development in the intrauterine growth retardation(IUGR)rats. Methods:①The establishment of rat model:female and male SD rats were copulated by 1∶3,and then were divided into the following two groups:IUGR group and normal group. The former were treated by 50% calorie compared with normal from gestational day 1 until term.②The collection of samples:pancreas of rat embryonic day14.5(E14.5),19.5(E19.5)and new born were dissected under microscope respectively.③The detection of pancreatic morphological changes:HE staining and light microscope were used.④The expression of Insulin/FoxO1/Pdx1/MafA genes:after abstraction of total RNA,the technique of RT-PCR was used to detect the expression of Insulin/FoxO1/Pdx1/MafA genes. Results:①Compared with normal,the pancreatic construction,islet area and quantities had abnormal morphological changes during pancreatic development.②The genes of Insulin/FoxO1/Pdx1/MafA began to be expressed from E14.5,and the expressions of Insulin and MafA were increased as the fetus grew while FoxO1 and Pdx1 were decreased.③Compared with the normal,the expressions of FoxO1 and MafA were lower in IUGR rats(P < 0.05),while Insulin and Pdx1 had no evident change. Conclusion:The expressions of Insulin/FoxO1/Pdx1/MafA genes were affected by intrauterine growth retardation.