An approach for estimating three-dimensional motion field of cardiac vessel axes recovered from X-ray angiographic sequences based on elastic registration is proposed.Displacement vector of each skeleton point is obtained by matching vascular axes at consecutive instants in point-by-point manner.A proper cost function is minimized to acquire the global optimal match by using the algorithm of dynamic programming.The accuracy of the method was quantitatively assessed by using computer-simulated data with known transformation parameters.Experiments with clinical data were also carried out.Results show the validity of the method.