Parabiosis is an experimental animal model in medical studies. This kind of animal models can realize the exchange of blood and body fluid between the two united animals very well, and makes it possible to observe all influences of these exchange in different aspects, ranging from blood to immunity. Over the past few years, based on parabiosis studies, heterochronic parabiosis animals are preferred to be used as conjoint models and to provide experimental basis for researches in cancer, endocrine, transplantation, neurology and stomatology and so on.