For the purpose of clinical application, this article presents a preliminary observation on the arterial supply of the knee joint in 57 fixed and fresh lower limbs, adopting topography, arterial cast, a rteriography and clearing of the specimens. There are more variations and common-stems of the articular branches on the right side. Each artery of the knee has its own characteristic morphology and special distribution. Whenever a local area has several sources of arterial supply, relationships between primary and secondary, superficial and deep arteries exist. According to their caliber, arteries of the knee may be divided into 3 groups. Besides the possibility for evaluating the degree of blood supply, variations in caliber are indications for estimating the size of neighboring arteries. Arterial blood supply of the whole knee area is comparatively even and symmetrical. The level of origin of all arteries supplying the Same area of the knee joint is constant, bearing a certain relation to one another. Besides, a brief discussion about the concept of "pure articular branch" and "musculoarticular branch", collateral arterial anastomosis, local "nonvascular area", relationship between prepatellar arterial network and the blood supply of patella is given.