Objective To instruct the presurgical therapy for the patients with unilateral cleft lip and palate by a retrospective study on the patients treated with presurgical nasoalveolar molding. Methods Fifty-eight patients with unilateral complete cleft lip and palate were treated with presurgical nasoalveolar molding. Relevant variables of alveolar cleft before therapy were measured and analyzed, and combining with the analysis of the treatment results, the alveolar deformity was classified. Results Among the 58 patients, lingual inclination were observed in 4 patients after presurgical treatment, and no lingual inclination was observed in the other 54 patients. The anterior alveolar cleft in sagittal and vertical direction (PP’-Y, PP’-Z), as well as the angle of healthy side (∠PTT’) had statistical differences between the patients with and without lingual inclination. Conclusion Patients with or without alveolar inclination might be related with the anterior alveolar cleft in sagittal and vertical value, and the anterior alveolar angle of healthy side. Patients with no alveolar inclination could utilize appliance to reduce the degree of alveolar cleft directly, while patients with alveolar inclination should correct inclination deformity first.