Six CO₂ Laser wounds made on vocal cord of 5 healthy dogs to evaluate the depth of penetration, the extend of thermal effect, and the difference of healing process varying intensity and exposure time of Laser. The depth of penetration become deeper with the increase of exposure time or intensity of Laser, although they were not exactly parallel. The increase of exposure time resulted in a more thermal effect to the marginal epithelium around the crater than the increase of intensity. When only the superficial layer of lamina propria was vaporized, complete reepithelization occurred in one week and complete healing in three weeks.