Abstract: Optical triangulation is a basic profilometry based on the collinear equation by using the triangular relationship among the object, light source and a camera to get the direct solution geometrically. This paper reviewed the domestic anthropometric studies, and pointed out the importance of the principle research to the relative exploration. According to the classification of optical profilometry, and following the collinear equation, the faults of simple photogrammetry in body measurement were pointed out, the principles of the passive triangular method as well as the laser sectioning，Gray code grating method of active triangulation have been described mathematically. The features of each method on body scan have been summed up and the misunderstandings about infrared body scanning were also discussed.

Key words: 3-D body measurement, body scan, trianulation, binocular vision, laser sectioning, Gray code grating