The segmental mandibulectomy should be performed, if mandiblie invasion is suspected clinically and radiologically. And if tumor is located to mandible very closely or when microinvasion to mandible is suspected, marginal mandibulectomy is recommended. But in segmental mandibulectomy, reconstruction is difficult and cosmetic problem remains. In this case, we performed modified segmental resection of mandible, preserving the inferior margin of mandible, and maintains the continuity of the bone, in mucoepidermoid carcinoma of parapharynx, invading mandible. We reviewed the diagnosis, pathology, and treatment, and report the case with reviews of literature.