Since the images vary much with different view points in the 3D reconstruction of coronary artery,it is impossible to get matching points using traditional methods.Therefore,we only manually got bifurcate points as characteristic points,and the number of points was few,thus the estimation of fundamental matrix was difficult.To overcome this problem,a method was introduced to enhance the geometrical accuracy from two noncalibrated serial two-dimensional angiographic projections.Using serial coronary artery angiograms,we could get many matching points.Thus we could calculate the epipolar geometry using Random Sample Consensus Paradigm (RANSAC) which was often used in the reconstruction of nature scene.The results show that the method proposed is accurate and robust for estimating the fundamental matrix in angiograms.