Objective To observe the effect of lipopolysaccharide (LPS)-mediated intrauterine infection on the expression of mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) in hippocampus of young rats. Methods 10-week-old male and female SD adult rats were paired in accordance with the 1:1 matching principle. Pregnant rats were divided randomly into control group (10 rats) and LPS group (20 rats). On the 10th day of pregnancy, LPS was injected intraperitoneally in the experimental group (66 μg/kg), and correspondingly, the control group was injected with the same volume of normal saline. Open field tests were used to detect the exploring ability of the new environment in the 48-day-old young rats. The lesions of the hippocampal tissues were observed by HE staining, and the expression of MR and GR were detected by immunofluorescence histochemical staining. Dexamethasone inhibition experiments were conducted to investigate the effects of pregnancy infection on the regulating function of the hypothalamic-pituitary-adrenal (HPA) axis in the offspring rats. Results Compared with the control group, the ability for rats in the LPS experimental group to explore the new environment was decreased. The neurons in the regions of CA1 and DG of the hippocampus were arranged disorderly. Pyknosis, karyorrhexis, and karyolysis were observed sparsely, and the expression of MR and GR in the CA1 was declined. The GR expression in DG region was increased, while the expression of MR and GR in CA3 region and MR in DG region did not change significantly. There were no significant changes in serum corticosterone (COR) level after injection of normal saline and dexamethasone injection. Compared with saline, the levels of COR in both groups were decreased after application of dexamethasone.Conclusion Pregnant rats in LPS experimental group could induce the decline on the ability of offsprings in exploring in new environment, which is related to the change of the expression of MR and GR and the decreased MR/GR ratio in all hippocampal regions of offspring rats.