According to application , medical temperature sensors will be group into 3 types : body surface temperature sensor, body cavity temperature sensor and disposable body temperature sensor. Body surface temperature sensor is used to measure skin temperature, while body cavity temperature sensor is used to measure the temperature of nasopharynx, esophagus, rectum, tympanic membrane and bladder. Furthermore, during blood heating or hemodialysis, appropriate assembled medical temperature sensor can be used to monitor the blood temperature. The body temperature is one of the body's vital signs, it is required to maintain constantly at 37℃ in order to ensure metabolism and other functions working, this is the common characteristic of all mammals. With the improvement of monitoring techniques and development of research in body temperature, people are paying more attention to body temperature indicator during clinical anesthesia.