Abstract: Objective To study the correlation between decelerating wave intensity（W₂）and left ventricular diastolic function in patients with coronary artery disease（CAD）. Methods Wave intensity（WI）was detected using Prosound α 10 color Doppler ultrasonograph（ALOKA,Tokyo,Japan）and W₂ of patients was recorded.E/A,DT,AT,IVRT,PVs,PVd,PVa,and PVa-dur were detected,and 6-minute walking distance（6MWD）of patients was recorded. Results Changes occurred in W₂,DT,AT,IVRT,and 6MWD when the left ventricular diastolic function was deceased.The W₂ was 2 500±1 401mmHg·m/s³,2 170±928mmHg·m/s³,870±400mmHg·m/s³,and 767±361mmHg·m/s³,respectively,when the left ventricular diastolic function was normal,mildly-,moderately-and severely-impaired.The W₂ decreased with the severity of left ventricular diastolic function impairment,especially with moderate to severe impairment（P=0.000）. Conclusion W₂ can be used as a valuable ultrasound index for the left ventricular diastolic function in CAD patients.