Abstract: The morphologic changes of mice skin after being irradiated by IPL were observed by a laser scanning confocal microscopy. The relation of the epithelial or dermal interaction with the intensity pulsed light (IPL) in different energy density was discussed. A mouse was chosen and moulted, and then irradiated by the IPL system in vivo under certain wavelengths with different energy densities. The morphologic changes of mouse skin were observed before and after (1d, 3d, 7d) irradiated respectively. The results were compared and analyzed. The function of dermal collagen during the renovating of the tissue was studied and the key factors were presented.