Objectives: To explore the clinical values on the diagnosis of congenital bicuspid aortic valve(BAV) and its complications with trans-thoracic echocardiography. Retrospective studies were performed on the clinical values of the diagnosis on 43 cases of BAV, including the subtypes, the combined aortic stenosis, regurgitation, vegetation formation and the dilation of ascending aorta, which were confirmed by the trans-esophageal echocardiography and operations in the superior hospital. Results: BAV of 41 over 43 cases were confirmed by TEE or operations in the higher level hospital, 19 cases were operated, and 24 cases were performed with TEE, only 2 cases were mis-diagnosed with a diagnostic accuracy of 93% on BAV with TTE. There were 29 cases of L-R infused type（70.7%）, 10 in R-N infused and 2 in L-N type. Aorta dilation was observed in 16 cases. Operations were performed on 17 cases with 10 of aortic stenosis (AS, medium to severe) associated with aortic regurgitation(AR), 5 in aortic regurgitation(medium to severe) and 2 cases of mild AS+AR+vegetations. The other 24 cases were not appropriate for operations and need long-term follow–up due to intact or mild injured valves in stenosis or regurgitation. Conclusions: Trans-thoracic echocardiography is the first approach on the screening and follow-up of the diagnosis and the associated complications of BAV, which can provide the detailed information on aortic valve and aorta to decide the operations indications and the strategies.