The purpose of this study were to investigate the national incidence of cleft lip and palate patients and the proportion and contribution of oral and maxillofacial surgeons in the treatment of cleft lip and palate patients using the medical records of the Health Insurance Review and Assessment Service from January 2009 to December 2013. Also, to comprehend the tendency of the treatment of cleft lip and palate patients, nationwide survey of 42 professors in oral maxillofacial surgery hospital were conducted. This results were compared with the previous survey results to know the change in trend. Incidence of cleft lip was 7.2 per 10,000 birth. Gender ratio of cleft lip surgery was 1.63 : 1(men : women) and cleft palate was 1 : 1.22. Proportion of unilateral cleft lip in whole cleft lip was 87% and unilateral cleft palate was 70.9%. Alveolar cleft surgery was done the most at 9 years of age and repair of velopharyngeal incompetency was done the most at 5 years of age. Oral and Maxillofacial Surgeons operated the 5.3% of cleft lip surgery, 9.3% of cleft palate, and alveolar cleft was 21.6%. The response rate was 36%(15/42). Respondents operate cleft lip surgery on average 3.5 times per year, cleft palate surgery was 5.8 times. Unilateral cleft lip surgery was most performed between 10 weeks and 3 months from birth and the most preferred method is Millard. They operated cleft palate surgery the most in 12 18 months from birth. The most preferred surgical technique was palatal pushback and did the soft and hard palate at the same time. Alveolar cleft surgery was the most frequently at 6 15 years old and correction of nasolabial deformity was conducted after growth was ceased. Repair of velopharyngeal incomepence was the most favored by Pharygeal flap and language therapy was mostly done. From the above results, we understood the incidence and overall treatment trend of the cleft lip and palate patients in Korea, and I think that this was meaningful for basic data about current situation and role of department of oral and maxillofacial surgery for treatment of the cleft lip and palate