Progressive aortic root dilation is very common in patients with conotruncal heart defects. Late complications like aortic regurgitation, left heart failure, and aortic dissection will amplify the risk of reoperation and affect survival. Therefore, it is necessary to have regular imaging follow-up to identify high-risk patients and reduce complications and fatality. Noninvasive evaluation of the mechanical property of ascending aorta can predict possible aortic disease and facilitate risk stratification.This article reviews the research progress of imaging evaluation of progressive aortic root dilation in conotruncal heart defects.