Gastric cancer is still one of the main health care issue and gastrectomy with lymph node dissection is the only chance to be cure. Even though the development and standardization of gastric cancer surgery, the morbidity of gastric cancer surgery was reported around 20% with less than 1% of mortality in East. In contrast, around 40% of morbidity and 10% of mortality was reported in West. There has been several indexes which can define the complications after surgery, but adapting it into clinical practice is sometimes difficult due to the heterogeneous opinion between surgeons. Thus for clear defining the complications after surgery, consensus between many surgeons and prospective cohort study is necessary. The purpose of this study is collecting the complications data after gastric cancer surgery and defining it with every week meeting by at least 6 or more surgeons' discussion.