We investigated the mechanism that TGF-beta1 influences the immuno-environment at maternal-fetal interface and affects embryo implantation, using mouse uterine horn injection model. The expression of MHC I antigen (H2-D1) and the chaperone of MHC II antigen (H2-DM) after anti-TGF-beta1 antibody or hrTGF-beta1 treated pregnant mice were examined by real-time PCR, western blotting and immunohistochemistry. The results showed that the number of implanted embryos of anti-TGF-beta1 antibody-treated mice was decreased compared with the control. The expression of H2-D1 and H2-DM on days 6 and 7 treated uteri was increased both at mRNA and protein levels. In hrTGF-beta1 treated group, the expression of H2-D1 and H2-DM protein was decreased, and the number of implanted embryos was slightly increased. Immunohistochemical studies revealed that H2-D1 and H2-DM were mainly localized to the primary decidual zone. The anti-TGF-beta1 antibody and exogenous hrTGF-beta1 treatment altered the intensity of H2-D1 and H2-DM signal but did not change their localization. These observations suggested that injection of anti-TGF-beta1 antibody affected the number of mouse embryo implantation, and regulated the expression of H2-DM and H2-Q10.