Abstract: Objective : To compare the difference of pharmacokinetics between the intraperitoneal chemotherapy with cisplatin in hypotonic solution and in isotonic solution and to provide a theoretical evidence for clinical use of intraperitoneal cisplatin therapy in hypotoinic solution. Methods : Twelve hybrid dogs were used as the experimental objective. Experimental groups were intraperitoneally administrated with cisplatin in hypotonic solution (cisplatin was prepared with distilled water), and the patients in control group received intraperitoneal chemotherapy with cisplatin in isotonic solution. (cisplatin was prepared with isotonic saline). After two groups all received intraperitoneal chemotherapy,the peripheral blood, portal blood and peritoneal fluid were collected in 15 minute, 30 minute, 1 hour,3 hour and 6 hour, respectively. The platinum amount of peripheral blood, portal blood, peritoneal fluid was quantitated by flameless atomic absorption spectrophotometry. Results : There was a significant decrease of the platinurn amount in peritoneal fluid of the experimental group, as compared with control group. There was no significant difference between the platinum amount in peripheral blood, the portal blood in experimental group and the control group. Conclusion : Administration of intraperitoneal chemotherapy with cisplatin in a hypotonic solution results in the diffusion amount of platinum in peritoneum to increase.