An optical tomographic imaging method is provided in which light from a light source is split into a measuring beam and a reference beam, the measuring beam being moved by a scanning optical system and guided to an object to be examined, the reference beam being guided to a reference mirror, and in which a tomogram of the object is generated from a return beam of the measuring beam reflected or scattered by the object and the reference beam reflected by the reference mirror. The method includes acquiring longitudinal sectional information on the object, calculating depth-position information on the object from the longitudinal sectional information, and acquiring a three-dimensional surface image of the object by controlling a reference-path length defined by the reference mirror and a scanning operation of the scanning optical system in accordance with the depth-position information on the object.