Objective:To compare the preliminary clinical effect of mitral valve replacement and mitral valvuloplasty on hypertrophic obstructive cardiomyopathy with mitral regurgitation.Methods:From January 2010 to December 2013, the patients undergoing cardiac surgery at Bakulev Cardiovascular Surgery Research Center in Russia were randomly divided into two groups: Forty-one patients received left ventricular outflow tract hypertrophy myocardial resection (Morrow operation) combined with mitral valve replacement (MVR) as MVR group; Forty-seven patients received Morrow surgery combined with mitral valve repair (MVr) as MVr group.The primary end point: death, secondary end point: thrombosis complications (cerebral infarction, peripheral arterial embolism), recurrence of mitral regurgitation and left ventricular outflow tract pressure difference were compared between the two groups.Results:In the MVr group, 6 cases were converted to MVR and were excluded from the study.The survival rates of MVR group and MVR group were 78.9% and 96.6%, respectively , and the thromboembolic free survival rates of MVR group and MVr group were 83.2% and 100%, respectively. The differences were statistically significant( P=0.034, 0.026, respectively). There was no significant difference in mitral regurgitation and left ventricular outflow tract pressure difference between MVR group and MVR group 24 months after operation( P=1.000, 0.934, respectively). Conclusion:Operation combined with MVR or MVr is an effective method to relieve left ventricular outflow tract obstruction and mitral regurgitation. Morrow operation combined with MVr can improve survival rate and reduce thrombosis complications.