Abstract: Objective To discuss the accuracy of three different methods of assessing the core temperature by comparing the differences among the temperature of axillary, bladder and pulmonary artery． Methods Twenty-six patients in the department of vascular surgery who were ready to take cardiac surgery requiring pulmonary artery catheter and urinary bladder, and their axillary, bladder and pulmonary artery temperature within 5 hours after the surgery were measured and compared． Results There was a highly positive correlation (r=0．972, P< 0．05) and good consistency between the temperature of urinary bladder and pulmonary arterial．The axillary temperature and pulmonary artery temperature were positively correlated (r=0．937, P< 0．05) and of good consistency． Conclusion Bladder temperature is close to the pulmonary artery temperature, which is a reliable temperature measurement method for critically ill patients．