Embryo attachment, a precondition of ruminant pregnancy, has been recognized to be related to apoptosis in endometrial epithelial cells (EECs). In ruminants, interferon tau (IFNT) is secreted by trophoblast of conceptus and works in a concentration-dependent style. To verify the function of IFNT in caprine embryo attachment, caprine EECs were dealt with IFNT at 0, 1, 10 and 100?ng/ml. In this study, IFNT arrested caprine EEC cell cycle in G2 phase and induced cell apoptosis at 1?ng/ml and 10?ng/ml of IFNT. Interestingly, pro-apoptotic protein FAS and PRβ together with anti-apoptotic proteins SP1 and IGF1R were all up-regulated at 1?ng/ml of IFNT. It demonstrated that IFNT at 1?ng/ml might induce caprine EEC apoptosis and keep a balance between apoptosis and proliferation. Furthermore, regulation of HOXA10, COX-2, PRL, PTEN and STAT3 pathway in caprine EECs was likely to be contributed by IFNT at 1?ng/ml to improve the chances for embryo attachment.