Abstract: Objective: To investigate the application of symmetric triangular flap in repairing incomplete unilateral cleft lips.Methods: Thirty cases of incomplete unilateral cleft lip were repaired with symmetric triangular flap.A vermilion triangular flap was designed in the affected side and inserted into the other side to repair the vermilion.Results: All the thirty cases achieved first phase healing,with symmetry nasal ala,satisfactory shape of the upper lip and inconspicuous scar.Conclusions: The method is rational and simple,and is easy to master.The shape of the upper lip and nose is satisfactory after repairing.