Abstract: A new technique for examining coronary arteriosclerosis of body is presented in this paper. Precordial region of body was irradiated by low power microwave beam, which was modulated by the movement of heart. Relative information of reflected modulation wave from chest was extracted and analysed by a microcomputer in frequency domain. Experiments have shown that spectrum components from healthy body mainly locate in low frequency and the magnitude of higher frequency line is small. On the contrary, the magnitude of spectrum line in higher frequency region from coronary arteriosolerosists is stronger than that from a healthy body.