Abstract： Objective　To investigate the different effects of lip repair on maxillary growth among patients with cleft lip and(or) palate, and also the possible mechanisms accounting for that differences. Methods　The lateral cephalometric analysis was applied to 84 Chinese patients with unilateral cleft lip and(or) palate at the early stage of permanent dentition, which included 32 UCLA, 20 UCLP (CP unrepaired), and 32 UCLP, and 37 normal Chinese of the same age as controls. Results　The patients with unilateral cleft lip and palate who had lip repaired while the palate was left unrepaired exhibited the similar inhibition on maxillary growth to those who had both lip and palate repaired but the patients with unilateral cleft lip and alveolus had much less inhibition on their maxilla. Conclusions　The cleft and tissue defect of patients with cleft lip and palate might be the main cause that induced the inhibitive effects of lip repair on maxillary growth.