OBJECTIVE: To observe the effects of single administration of carboplatin by different ways on drug accumulation concentration and treatment of tumor tissue before surgery. METHODS: 60 patients with resectable advanced gastric cancer were randomly divided into intraperitoneal administration group (30 cases) and intravenous administration group (30 cases). All patients received 50 mg/m2 Carboplatin injection, intravenous administration, it stopped 4 weeks after continuous 5 d, repeated 3 times, when the last chemotherapy, intraperitoneal administration group was given 30 mg/m2 Carboplatin injection, adding into 750 ml 0.9% Sodium chloride injection, and placed in 37 ℃ water bath for preheating, taking paracentesis for disposable rapid injection. Intravenous administration group was 30 mg/m2 Carboplatin injection, adding into 750 ml 0.9% Sodium chloride injection, by intravenous infusion within 30 min. Both groups were administered once for at least 1 week, then surgery was taken after 5 d. The carboplatin accumulation concentration in 2 groups was determined after 160-180 min and 250-260 min, respectively, and the efficacy in the 5th day and incidence of adverse reactions during treatment were recorded. RESULTS: The total effective rate after 5 d, peritoneal fluid, portal vein and peripheral blood after 160-180 min, and carboplatin accumulation concentration in cancer tissues, adjacent normal tissues, peritoneum, omentum and negative lymph node after 250-260 min in intraperitoneal administration group were significantly higher than intravenous administration group, the incidence of adverse reactions was significantly lower than intravenous administration group, the differences were statistically significant (P<0.05). CONCLUSIONS: Compared with intravenous infusion, intraperitoneal injection of carboplatin before surgery can improve the local accumulation concentration and chemotherapeutic effect and reduce incidence of adverse reactions.