The stratum corneum layer of the skin plays critical roles in maintaining the integrity of skin structure and barrier function. Its noninvasive monitoring is therefore very important. In this in vivo study, the mouse ear was used as a model. The acetonemediated exfoliating process was monitored by timedomain optical coherence tomography (TDOCT). Results demonstrated that OCT imaging could be used to obtain the thickness of the stratum corneum layer and to monitor the exfoliating process. OCT imaging has clinical potentials in studying the structure and function of skin barrier.