A immunohistochemical (ABC methods) methods was used to study the 5-Hydroxytryptamine (5-HT) cells generant process in the Gastrointestinal Tract of the postembryonic development of Rana amurensis . The result show that the 5-HT positive cells were first found in the stomach at stage 38,and first found in the Small and large intestine at stage 41.With the development of the gastrointestinal tract, the location of the 5-HT cells were changed a lot, between the mucosal epithelium, the basal part or the between alveolar epithelial cells. But the shape of cells not have clearly changed, they were mainly round, ellipse, cone-shape and shuttle-shaped.The occurs time of 5-HT cells,the location and shape were conformable with needs of growth, and the function of each segment of the gastrointestinal tract.