Abstract: The localization of GRP in the uterus and/or placenta of non-pregnant or pregnant Sika deer was studied immunohistochemically. The strong immunoreactions were identified in the supra-nuclear region of the epithelial cells of the uterine glands of the placenta, however, no reaction was observed in the uterus of non-pregnant or immature animals. GRP may play an important role as the critical signals or nutrients for the growth of fetus in the synepitheliochorial placenta.