Abstract: In order to calibrate the coefficients of phase-height mapping equation in phase measuring profilometry (PMP) systems,virtual planes were introduced. Firstly,the intrinsic and extrinsic parameter, of camera and projector were calibrated with uniforni mathematics model and processing method,as a projector could be considered as a camera working in reverse.Secondly,geometric construction of the measurement system was calibrated by means of stereovisiou method.Thirdly, a reference plane was defined in the measuring volume.Phase distribution of reference plan and parallel standard planes at different distances from the reference plan was worked out according to the calibrated parameters.Finally, the coefficients of phase-height mapping equation were obtained with least square method.The standard deviation of measurement reached 0.046mm.A model consists of four steps with space of 1.00mm was also measured. The measured average height between neighbor steps was 0.99mm.The experiment results reveal that the method is feasible.The procedure of system calibration is simplified.