Abstract: Sixty three crossbred gilts (Landrace × Yorkshire) were used to investigate the effects of feed intake level on maternal immunoglobulins concentration in serum and interferonα(IFNα), interferonβ(IFNβ), interferonγ(IFNγ), myxovirus resistance(Mxl), Tolllike receptor 4(TLR4), interleukin10(IL10), tumor necrosis factorα (TNFα ) mRNA expression in uterus and embryonic survival during early pregnancy. The gilts were randomly allocated into three feed intake levels (High(H): 273 kg·d-1；Medium(M): 164 kg·d-1；Low(L): 082 kg·d-1) after mating. Gilts were slaughtered on d12, 25 and 35 of pregnancy, serum, uterus and embryos were collected. The maternal immunoglobulin concentration in serum was determined by Nephelometry, and real timequantitative RTPCR was applied to determine the genes expression difference in uterus and embryos. The results showed: ①Maternal immunoglobulins concentrations in serum were higher in H and M than that in L (P<005) and no significant difference between H and M groups (P>005). ②IFNα, IFNβ, IFNγ, Mxl, TLR4 and IL10 genes expression in uterus and embryo were increased in M group compared to that in L group(P<005), but TNFα genes expression were greater in L group than in M group (P<005) and no significant difference between H and M groups (P>005). ③Embryonic survival rate on d12 were higher in M group than that in H group (P<005) and no significant difference between M and L groups (P>005), and embryonic survival rate on d25, 35 were elevated in M group and no significant difference between H and L groups (P>005). It was concluded that high and medium feed intake levels improved the maternal and embryonic immunoprotection during early pregnancy，low feed intake level significantly decreased the maternal immunoglobulins and down regulated the expression of immunerelated genes in uterus and embryos and may had detrimental effects on the survival of embryo.