Optical coherence tomography is an appropriate imaging method for biomedical science, due to its advantages of noninvasive nature, high resolution and fast imaging speed. Because most biological tissues have the characteristic of high scattering coefficient, OCT system can just obtain the structural images several millimeters below the surface of the tissues. The superficial depth of OCT’s penetration limits application in dermatology field. As a common disease, the port wine stain (PWS) is a indication of OCT, because of its superficial lesion and significant expansion of blood vessels. To get deeper penetration in the skin, the authors employed 1 310 nm superluminescent diode as light source, optimized the light intensity ratio of reference delay arm and sample arm and control polarization, and the research of PWS imaging in vivo was accomplished. Besides, OCT is able to gather clear image and key characteristic parameters, such as the depth of epidermis layer, the diameter of blood vessel, etc. OCT will play an important role in the diagnosis and therapy of PWS.