Our previous study demonstrated that Staphylococcal enterotoxin B (SEB) administration during pregnancy could alter the percentage of T cells subpopulation in the thymus of the neonatal rats; however, little is known about the effect of maternal SEB administration during pregnancy on T cells subpopulation in the peripheral blood of the offspring rats. In the present study, pregnant rats at gestational day 16 were intravenously injected with 15 μg SEB. The present study found that prenatal exposure to SEB significantly decreased the percentages of CD8 T cells in the peripheral blood of both neonatal rats on the fifth day after delivery and the adult offspring rats. Furthermore, it significantly increased the percentage of CD4 T cells as well as the ratios of CD4 to CD8 T cells in both neonatal and adult offspring rats. Prenatal exposure to SEB significantly decreased the expression levels of IL-4 and IFN-γ in the plasma of neonatal and adult offspring rats. Furthermore, SEB restimulation significantly increased the percentage of CD8 T cells and significantly decreased the percentage of CD4 T cells. These data suggest the prenatal exposure to SEB can imprint the increased CD4:CD8 T cell ratio in the peripheral blood from the neonate to adulthood through the decreased CD8 T cells and the increased CD4 T cells, and altered the response characteristics of CD4 and CD8 T cells to secondary SEB administration in the peripheral blood of the adult offspring rats.