The ultrastructural changes of wound healing process following abrading of the laryngeal mucosa with a smooth file in 16 guinea pigs were observed by scanning and transmission electron microscopies. The results showed that: 1. the repair of the laryngeal mucosa epithelial defect was initiated from mobilization and migration of residual basal cells in the surrounding tissue onto the denuded epithelial surface; 2. the regenerated epithelium of migration covered small part of the denuded epithelial surface 24 hours after sustaining the injury; 3. five days later, all denuded epithelial surface was covered by the regenerated epithelium; 4. differentiation of the regenerated epithelium began 10 days after abrasion, and was completed 21 days after abrasion; 5. tonofilaments of distributed the minority, permeation, and concentration were seen in those cells of the regenerated epithelium respectively on the 1st, 5th and 10th days after abrasion. Particularness of differentiation of the regenerated epithelium was discussed.