The efficacy of ultrapulse CO₂ laser system was assessed in treating divided nevus of the eyelid. 48 patients who were 1~45 years old with divided nevus of the eyelid were treated by a ultrapulse CO₂ laser, with 1 mm spot size diameters with related energies from 60 to 100 mJ and pulse lengths of 1 ms. All treatments were given at 3~6 months interval. After 1~4 times of treatment, 13 cases were cured, all lesions of 22 cases were significantly dissipated, and 13 cases were improved. Several side effects were observed including two cases each of infection,scar and hypopingmentation respectively. The ultrapulse CO₂ laser offered efficient treatment of divided nevus of the eyelid and side effects were minimal.