Multislice computed tomography (MSCT) is noninvasive and 3D imaging compared with the traditional coronary angiography (CAG). An optimal CAG viewing angle algorithm based on MSCT vessel analysis is proposed. First, a local vessel enhancement based on optimal oriented flux and locally adaptive threshold region growing is applied to extract the 3D coronary arteries model and then 3D thinning is performed and segment of interest is selected. According to the parameters during CT and CAG data acquisition, a perspective projection is performed to simulate the CAG procedure and the optimal viewing angle is calculated with the minimum foreshortening and minimum overlapping principle. Experimental results illustrate that the foreshortening percent is less than 1% in the obtained angle,which is close but superior to the working view angle. Therefore it can be applied to coronary artery disease intervention planning.