Abstract: A method for measuring the local temperature in the body of human or animal is provided. In the method, a first ultrasonic wave is transmitted to a region to be measured, which has temperature T, under the guiding of M-type ultrasound. The reflected ultrasonic wave from a particular reflection surface is received to obtain a first parameter. Then the temperature of the region to be measured is modified to T+?T. A second ultrasonic wave is transmitted to the region to be measured. The reflected ultrasonic wave from the second ultrasonic wave reflected by a particular reflection surface is received to obtain a second parameter. A ratio of the measured value of 2nd parameter to that of 1st parameter can be obtained. On the other hand, a theoretical ratio of the second parameter to the first parameter can also be obtained through theoretical calculation. The objection function which involves the differences between the theoretical ratio and measured ratio can be minimized by an optimization method.