A submucous cleft palate(SMCP) is characterized by a midline deficiency or lack with/without incorrect positioning of muscular tissues in the soft palate, and by a bony defect in the midline or the center of the hard palate. Velopharyngeal incompetence(VPI) related to this SMCP has been managed by various surgical and prosthetic techniques. Because the individual diagnosis and treatment of SMCP patients was not easy to the speech pathologist and to the maxillofacial reconstructive surgeons, and for the better understanding and for the ideal approaches to the SMCP patients, we reviewed several recent articles about grading system in the SMCP caused by VPI, and summarized in this review article.