Abstract: The in-situ characterization of the three-dimensional microscopic morphology on the wear surface is conducive to reduce the deviation of the measured value from the real size. More detailed information on surface profile might be acquired to explore the morphological evolution of the wear surface during the tribological process. In the work, the wear surfaces had been in-situ characterized by using the visual system attached to the reciprocating tribometer. At different friction stages, the in-situ observation of the target areas on wear surfaces of titanium alloys had been carried out. Once the two-dimensional optical images had been collected, the shape from shading (SFS) technique based on the optimization of illumination model had been performed to generate three-dimensional reconstructed view of microscopic morphology of the target area on the titanium alloy wear surface. Height parameters of the target areas had also been obtained by calculation after three-dimensional reconstruction process. To validate the reliability of SFS technique for three-dimensional reconstruction, the target areas of the wear surface of titanium alloy had been analyzed on a laser scanning confocal microscope (LSCM) to obtain the three-dimensional topographic images and height parameters as the reference for comparison. It was found that three-dimensional reconstruction of target areas on the wear surface with varying degrees could be carried out by SFS technique with both Lambert illumination model and Phong illumination model which had been applied to describe the nature of reflection of the incident light on the wear surface. More importantly, the three-dimensional reconstructed topographic images derived from Phong illumination model were more consistent with the surface morphology obtained by laser scanning confocal technique. The geometric features on wear surfaces were well textured. The relative deviations of the height parameters of areal field parameter from the LSCM values were also smaller.