In this paper, a novel three dimensional profilometric measurement system based on a computer aided image processing technique is presented. This system consists of a single mode optical fiber coupler with phase shifting as the grating projector. A piezoelectric (PZT) cylinder wrapped by one arm of the optical fiber coupler is utilized to introduce phase shift. Results have been obtained in the practical measurement with this measuring system. This system, owing to the advantages of quite simple optical configuration, extremely small size and light weight, high visibility and sinusoidal intensity distribution, would find high practical value in applications.