To observe the pathologic changes of normal tissue in nude mice after peritoneal perfusion with hyperthermia, hyper-osmolar solution and mitomycin C (MMC). Fifty BALB/c nunu mices (7-10 weeks old) bearing HT-2 lines were chosen for the study, and were randomly divided into five groups: isotonic solution (control group), hyperosmolar solution (HOS group), HOS plus MMC group, hyperthermia (HT group) and HOS plus HT plus MMC group. After continuous hyperthermic peritoneal perfusion (42℃/30min) with 7.5% NaCl and 5μg/ml MMC, the liver, spleen, small intestine and kidney were examined by light microscopy. Results: ①In HOS and HOS plus MMC groups, no changes of liver, spleen and kidney were found. ②In HT and HOS plus HT plus MMC groups, slight degeneration of liver, hyperemia of spleen, swelling of kidney tubule cells and small intestine were found. ③In HOS plus HT plus MMC group, partial loss of small intestinal villi were also observed. Conclusioin: After continuous hyperthermic perfusion conbined with hyper-osmolar solutions and mitomycin C, a slight injury was showed in normal tissue of nude mice.