The temperature distribution produced by a HIFU (High Intensity Focused Ultrasound) transducer has been investigated by a set up using T type thermocouple temperature sensors in the automated scanning system. The temperature change and the temperature distribution due to applied ultrasound power have been characterized. The temperature measurements were carried out in a tissue-mimicking material (TMM) that has characteristics very similar to human tissue and in ex vivo tissue. A temperature measurement set up in a tissue phantom has been constructed at TÜBİTAK UME (The Scientific and Technological Research Council of Turkey, the National Metrology Institute) Ultrasound laboratory. Burning and removing the tissue by high power ultrasound have been showed.