Salivary gland tumors take possession of almost 5% in head and neck malignancies. Among these, mucoepidermoid carcinoma(MEC) is most common malignany in major salivary glands(12-29%) and the parotid gland is most predilection site. Intra-oral MEC has a tendency to various locations, and the predilection sites are palate, cheek, mandible, lip and tongue in order of frequency. A few cases of MEC are occurred in with retromolar trigone, oropharynx, and ectopic salivary gland. Recently, we experienced a-65-year old woman with retromolar trigonal mass, and she was finally diagnosed as MEC. We report it with review of literature.