Abstract: Objective:To investigate the therapeutic effect of improved triangular flap in repairing the unilateral incomplete cleft lip.Methods:Twenty-five patients with unilateral incomplete cleft lip were treated with the improved triangular flap.The contralateral philtrum ridge acted as a reference in fixing the surgery point;the nasal alar basal muscles were separated,a complete orbicularis oris muscle ring was reconstructed and the two sides of the lip were kept at the same height.Results:The operation was successful in all the cases.The nostrils were in symmetry,the scars were at the philtrum ridge,the labial archs in good shape and the rosylips well-stacked.All the twenty-five patients were satisfied with the results.Conclusions:The improved triangular flap may present a symmetrical nasolabial region and natural shape.It is an effective procedure for repair of the unilateral incomplete cleft lip