[Abstract] Objective: To compare the effect of irrigation fluid temperature on patients’ body temperature and hemorheology during plasmakinetic resection of prostate (PKRP) by urethral. Methods: 60 elderly patients scheduled for PKRP were selected for the study, ASAI-III. L2-3 combined spinal epidural anaesthesia was applied. The 0.9% sodium chloride solution was chosen as the irrigation fluid. The patients were randomly divided into two groups using different temperature and volume of irrigation fluid. There are 30 patients in each group .. group I use the irrigation fluid of room temperature; while group II use the fluid of 37oC. Observating the patients’ rectal temperature, blood temperature, heart rate, and measuring hemoglobin (Hb) , hematocrit (Hct) , the indicators of plasma electrolytes and hemorheology by extracting venous blood before operation (T0), at the end of operation (T1), 6 hours after operation (T2) and 24 hours after operation (T3). Results: The temperature of the patients after operation in group I was significantly lower than that before surgery (P<0.05)， while group II has no significant changes. There is on significant changes of electrolytes in both of the two groups. Hematocrit changes in different degrees. Whole blood viscosity and viscosity were reduced in both groups,， but groupI was significantly 24hours after operation. Conclusion:The temperature of irrigation fluid during PKRP can cause the changes of patiengts’body temperature and hemodilution. hypothermia can increase blood viscosity after surgery.