OBJECTIVE To study the proper sites and doses of intraoperative radiotherapy (IORT) for gastric carcinoma and the effects of this treatment.METHODS A total of 106 cases of stage Ⅰ- Ⅳ gastric carcinoma who received a D2 or D3 radical resection operation combined with IORT were analyzed. Sixty-seven patients with gastric cancer of the antrum and body received distal gastrectomy. The sites of irradiation were at the celiac artery and hepatoduodenal ligament area. Another 39 patients with carcinoma of the cardia and upper part of the gastric body and whole stomach received proximal gastrectomy or total gastrectomy. The sites of irradiation for this group were the upper margin of the pancreas and the regional paraaorta.The therapeutic effects (including survival and complications) of these 106cases who received a combined operation IORT (IORT group) were compared with 441 cases treated during the same time period by a radical resection operation alone (operation group).RESULTS The radiation dose below 30 Gy was safe. The therapeutic method of the operation combined with IORT did not prolong the survival time of patients with stage Ⅱ and Ⅳ gastric cancer, but the 5-year survival rates of patients with stage Ⅱ and Ⅲ gastric cancers were significantly improved.While the 5-year survival rates of the stage Ⅲ cancer patients receiving D2 resection combined with IORT had marked improvement, for those receiving a D3 radical resection, only the postoperative survival rates at 3 and 4 years of those cases in stages Ⅲ cancers were improved (P＜0.005-0.001). The 5-year survival rate for those patients was raised only 4.7%(P＞0.05).CONCLUSION The 5-year survival rates of patients with stages Ⅱ and Ⅲ gastric carcinoma who received a D2 lymphadenectomy combined with IORT were improved and had no influence on the postoperative complications and mortality.