A method was proposed to calculate the optimal views of segment of interest based on 3-D reconstruction of coronary arterial tree. The optimal views ware obtained by choosing views with minimal vessel overlapping from a set of anglographic views with minimal vessel foreshortening. Theory X-ray perspective projection and OpenGL perspective projection is analyzed and compared, then the projection of coronary arterial tree in optimal view is displayed by using OpenGL. The experiments show the assessment of lesion length and idameter narrowing can be optimized based on the projection in optimal view,and it can be utilized to assist interventional cardiologists in planning a coronary intervention.