3-D profilometry based on modulation measurement (MMP) depends on the modulation distribution of the sinusoidal fringes projected on objects. The projecting direction is the same as the detecting direction, it can measure the objects with shadow, discontinuous height steps and spatial isolation on them. The detailed introduction on the principle and processing method of MMP and the measuring results for an object are presented. The results proved that MMP was correct in principle and effective in actual measurement. This method will be useful for 3-D profilometry、 3-D sensing and machine vision etc.