Prior to starting clinical cardiac allotransplantation, cardiac xenotransplantation was performed in human in 1960s. In 1964, Hardy performed cardiac transplantation using a chimpanzee heart and Bailey performed cardiac transplantation using a baboon heart to an infant with hypoplastic left heart. The use of cyclosporine has greatly improved the outcome of clinical cardiac transplantation and cardiac allotransplantation became an established treatment strategy for the patients with end-stage heart failure. Although concordant cardiac xenotransplantation from a primate to a human may be successfully performed using current immunosuppressive regimen, a primate heart is not a good candidate for cardiac xenograft due to animal light issues and its size. Therefore, many investigators have tried to extend the survival period in discordant xenograft from pig to primate, but no prolonged surviving orthotropic cardiac xenograft has been established yet. In this review, experiments of concordant and discordant cardiac xenografts which were performed by the authors were introduced.