A 68-year-old male with sudden back pain and cardiogenic shock status transferred to our ward. Transthoracic echocardiography revealed that the abnormal round shape string was in the left ventricular outflow tract. The continuity from the staring to the aortic valve was unclear. Intimal flap could not be detected at the level of the ascending aorta. Color Doppler flow imaging showed that the severe AR jet extended into the round string. TEE showed that the intimal tear and flap was seen just above the left subclavian artery. Preoperative diagnosis was acute Stanford type A dissection and acute severe AR due to the inversion of the proximal intimal flap to the left ventricular outflow tract through the aortic valve. At operation, the proximal intimal flap was dissected circumferentially and was cut all the way around 8 cm above the aortic valve ring and was inverted to the left ventricular outflow tract. The aortic valve was preserved because of its normal character after exclusion of the proximal intimal flap. Ascending and arch replacement was carried out. Postoperative TEE and TTE slowed no findings of AR. The patient's postoperative course was uneventful. To our knowledge, this is the first reported case that severe AR caused by the proximal intimal invagination to the left ventricle.