Although the riding comfort of tilting trains has been managed by setting allowable limits of roll motion in Japan, it is impossible for this approach to express the psychophysical relationship between various vibrational factors and riding comfort. In order to propose a function to evaluate the riding comfort of tilting train on transition curves, an experiment was performed with the E991 series test train (TRY-Z). Twenty-eight subjects participated in this experiment. As a result, by referring to some international standards on the method of evaluating riding comfort, a modified method was proposed to evaluate the lateral vibration in addition to the roll motion on curve transitions.