Through the immunohisto chemistry SP methods, it was studied that whether the expression of Vimentin, cytokeratins and cytokeratin-7 could be specific mark of yak stroma cell and epithelial cell before and after implantation. The results showed: Vimentin was a specific mark of yak stroma cell before and after implantation. The cavity epithelium, epithelium and allantoic inner layer cell were only marked by CKs. The allantoic outer layer cells were comarked by CKs and CK7.