Objective To evaluation clinical significance of CTA and CTPI in the blood supply and hemodynamic of gastric cancer. Methods 88 patients with gastric cancer were selected in this study. 63 patients were scanned by perfusion CT, and the relationship of blood flow (BF), blood volume (BV), permeability surface (PS) and mean transit time (MTT) with local invasion of gastric cancer and differentiation were analyzed. 27 cases received dynamic enhanced scanning and the location of the stomach arterial blood vessels and cancer were analyzed. Results 20 patients in 27 cases of underwent dynamic enhanced scanning clearly displayed the proper hepatic artery, celiac axis, left and right gastric artery and right gastroepiploic artery on the VR. MIP showed that the small blood vessels and stomach blood supply was related to the location of the tumor growth. The blood vessels that supply the gastric cancer were largely from their own blood vessels of the stomach. There was significant difference in BV, BF, PS, MTT and T staging. MTT could reflect the general classification of gastric cancer histological characteristics. There was significant difference of PS in middle and high differentiated group compared with poorly differentiated group. PS had no significant correlation with BF, BV and MTT. Conclusion CTA could clearly display the stomach tumor and blood supply, and CTPI can reflect local invasion and differentiation degree of gastric cancer to some extent.