Individuals with cleft lip and palate often require orthognathic surgery to estabilish facial harmony and optimal occlusal function because cleft induced secondary deformities of maxilla and mandible have been taken for the worse as growing up. During operation many problems as like residual oronasal fistula, bony defects, soft tissue-scarring from previous surgery, and the congenital absence of the maxillary lateral incisor teeth with cleft-dental gap are encountered and interfere the operation. In this retrospective study 16 patients who were performed orthognathic surgery from the January. 1991 to the March 1997, could remind the clinically important problems of the orthognathic surgery and suggest more easy, safety, and accurate methods to solve these problems. The preperative and postoperative cephalometric skeletal and soft tissue data were compared and many problems which could encounter during operation were checked and reviewed many historical experiments and newly suggested articles, so some results can be suggested as like: 1. The sum of maxillary advancement(mean 5.14mm) and mandibular retrusion(mean 6.71mm) is about 11.85mm. Two-jaw surgery is recommended because the scar of upper lip and palate limit the maxillary advancement. 2. Upper lip tightness interfere the soft tissue movement after bone segment mobilization, release of tightness improve the soft tissue profile. 3. Soft tissue profile is most important in orthognathic surgery.4. Soft tissue response to orthognathic surgery is not different in secondary cleft deformities and simple malocclusion patient but amount of soft tissue response is not constant in many experimental study. 5. Camouflage mandibular surgery is benefit in some maxillary deformity patient.