A double integrating sphere system was developed to investigate the effect of the osmotic agent of glycerol on the optical properties change of mouse skin. The results showed that the reduced scattering coefficient of mouse skin reduced, and the absorption coefficient increased when rate skin was immerged during the initial 25 min, and then the optical properties of rat skin approached to constants. The changes in absorption and scattering parameters resulted in reduce of the effective attenuation coefficient. This study provides a new method to investigate the control of optical properties of tissu. It is important for optical imaging of tissue.