The origin, branching and distribution of the superior mesenteric artery were observed on 100 Chinese adult cadavers. The average level of the origin of the superior mesenteric artery lay on the middle third of the body of the first lumbar vertebra. The distance between the origins of the superior mesenteric artery and the coeliac artery and the diameter of the superior mesenteric artery were measured. The superior mesenteric artery usually gave off two (47％) or three (39％) colic branches. The relationships of the origin of each colic branch, originating directly from the superior mesenteric artery, to the third part of duodenum or the head of pancreas and also to the origins of the intestinal arteries were observed. The extent of distribution of each colic branch was estimated. Most of the superior mesenteric arteries (82％) did not distribute so far as the left colic flexure. The pattern of branching of the ileocolic artery may be divided into four types. The symmetrical and ansal types were the prevailing types, they were present in 45.26％ and 42.11％ respectively. Nearly half of the appendicular arteries (45.56％) arose from the ileocolic artery, about 34.44％ appendicular arteries arose from the ileocolic ansa. Usually the appendicular artery was the first branch of the ileocolic trunk. The superior mesenteric artery gave off 15.9 intestinal branches in average. In 76％ cases, the inferior pancreatic-duodenal artery and the first intestinal artery originated from a common trunk and this trunk usually arose from the posterior aspect of the superior mesenteric artery. We found that in 13 cases the superior mesenteric artery gave off common hepatic artery or right hepatic artery.