Objective To further definite the distribution of caudal arteries and veins of rat by anatomical dissection and to deepen the understanding of their physiological functions, and provide a basis for standardization of animal experimental techniques and design of animal models. Methods Eighteen SPF adult SD rats were used in this study. Several techniques were used in combination to study the anatomy and histology of the rat tail blood vessels: paraformaldehyde perfusion through the abdominal aorta was performed for rapid and thorough fixation, blue and red paints were injected to visualize the tail veins and arteries, respectively, arterial microangiography was performed to illustrate the distribution of tail arteries, and the microscopic structure of arteries and veins was verified by histological examination. Results Three longitudinal superficial arterial and venous systems of rat tail were confirmed and a dorsal arterial and venous chain structure was defined, which deeped our knowledge about the distribution of the deep blood vessels. In addition, the caliber of arteries was not corresponding with that of veins, providing a basis of their physiological functions. A bilayer cage connecting structure of the rat tail vasculature was for the first time defined. Conclusions The rich vascular structure of rat tail is described in details in this study. The existence of basal vascular system of rat tail is clarified. A concept of bilayer framework of the rat tail vasculature is proposed, which lays a good foundation for related researches of their physiological functions, and provides a good basis for avoiding major injuries and compensatory responses of hindlimb ischemia during animal experiments.