Objective:To analyze the incidence of functional mitral regurgitation (FMR),post-operation characteristics and operation indications of Marfan patients with severe aortic regurgitation and giant left ventricle.Methods: The clinical data and the follow-up data of 19 Marfan patients with severe aortic regurgitation (≥10 ml) and giant left ventricle (LVEDd≥7.0 cm),who were treated from Jan.2000 to Dec.2007,were analyzed retrospectively.Results: All patients received Bentall operation and there was no perioperation death.Follow-up was 72 patient-year (ranging 3 months-7 years).The degree of FMR decreased obviously after operation,with an improvement rate of 87.5%,and the FMR almost disappeared 6 months to 1 year later.Conclusion: Bentall achieves good outcome in Marfan patients with severe aortic regurgitation and giant left ventricle.Mild to moderate FMR(<10 ml) disappears with the decrease of the left ventricle size.For patients with severe FMR (≥10 ml) complicated with dysfunction of left ventricle,managed ventricular pacing is suggested.