Laparoscopic surgery has been widely performed for early gastric cancer. However, laparoscopic surgery has some disadvantages from the limited view of the operative field. Moreover, the topological patterns of vessels in the stomach are complex and varies between patients. Therefore, it is difficult to ligate the gastric arteries and veins in laparoscopic gastrectomy. In this study, we proposed a vessel navigator to guide an optimal path to the target vessels. The proposed method used a topological vessel map obtained from the abdomen computed tomography angiography images. In addition, it was designed to guide the optimal route to the target vessels from the present point. For this purpose, we defined a penalty function to measure how difficult a suggested pathway is compared with the other one. To assess the feasibility of the proposed vessel navigator, we applied to several steps of the laparoscopic gastrectomy.