Forty-six patients with advanced gastric cancer were investigated. 25 patients were randomized to receive intraperitoneal hyperthermic (43℃) hypotonic perfusion with high dose cis-diamminedichloroplatinum (60-200mg/m2 body surface) and sodium thiosulfate intraveneously (7.5g/m2 body surface). The time of the intraperotineal perfusion was 30 minutes with the total volume of the perfusate of 2500-3000ml. 21 patients were only operated. The sex ,age macro-or microscopic serosal invasion, and histologic type of two groups were similar and comparatible. We found no cancer cell in nine paients with positive intraperitoneal free cancer cell in the treated group. The postoperative 1-year survival rate of patients in the treated group (96.00%) was significantly higher than that of the random control group (48.54%), Ｐ＜0.01. The postoperative 1 1/2year survival rate in the treated group (68.88%) was also higher than that of the control group (40.00%), however, with no significant difference (Ｐ＞0.05). No serious myelosuppression, kindley,liver, and peripheral nerve damage, and other complications were found. The results indicated that this therapy is reasonably safe and could be a prophylactic theapy for the peritoneal recurrence after radical gastrectomy, which should be further investigated.