Abstract: Objective To explore the differences between two types of bicuspid aortic valve （BAV） patients in clinical and echocardiographic features. Methods Clinical and echocardiographic data about BAV patients who admitted to our hospital from November 2008 to June 2014 were retrospectively analyzed. Results Of the 81 BAV patients， 29 patients were Type Ⅰ（A-P type）BAV and 52 patients were Type Ⅱ（L-R type） BAV. Baseline demographics and left heart function were similar between two groups. Type Ⅰ group had higher incidence of moderate-severe aortic regurgitation （AR） and enlarged aortic sinus than that of Type Ⅱ group（P＜ 0.05）. Type Ⅱ group had higher incidence of moderate-severe aortic stenosis （AS） than that of Type I group （P＜ 0.05）. The incidence of enlarged ascending aorta were similar between two groups （P=0.300）. Type I group had larger aortic annulus， sinus and sinotubular junction dimensions compared to Type Ⅱ group （P＜ 0.05）. There was no significant difference in ascending aorta dimensions between two groups （P=0.146）. Conclusion BAV is dominant in L-R type. A-P type is dominant in moderate-severe AR，L-R type is dominant in moderate-severe AS. A-P type patients have larger aortic annulus， sinus and sinotubular junction dimensions than that of L-R type patients.