OBJECTIVE: To investigate the therapeutic effect of flap transplantation in repairing soft tissue defects of children. METHODS: From January 1997 to May 2002, 75 cases of different soft tissue defects (52 males and 23 females, with the age of 3-14 years) were repaired by axial and non-axial flaps transfer, and axial flaps transplantation by microvascular anastomosis. The flaps area ranged from 3 cm x 5 cm to 15 cm x 42 cm. Emergency operation was performed in 26 cases and secondary operation in 49 cases (infective wound such as osteomyelitis and plate extra-exposed of fracture). The defect regions included the forearm, back of the hand, thumb, index finger, leg and foot. The types of flap graft and application range included 39 cases of axial flaps transfer or transplantation (27 cases of along- or contra-transfer of transplantation and 12 cases of microvascular anastomosis). The non-axial flaps transfer were designed along- or contra-transfer near the wound area in 36 cases. The ratio of length to width was 2.5:1-3.5:1 in 27 cases, and larger than 3.5:1 in 9 cases. Adequate anesthesia method should be chosen according to the characteristics of children, non-traumatic operating during surgery and postoperative supervision and nursing of flaps should also be paid enough attention. RESULTS: After operation, blood circulation crisis occurred in 2 cases (1 case of artery failure and 1 case of vein failure). The flaps survived in 37 cases and partially survived in 1 case and necrosed in 1 case. The survival rate was 96.2%. The postoperative follow-up period was 3 to 60 months, the blood supply, elasticity and texture of flaps were good. The effect of repair was satisfactory. CONCLUSION: Different types of transplantation of blood-supply of flaps may repair the different types of soft tissue defects in children. Free flap transplantation is safe and beneficial in children, different defects of soft tissue were repaired by axial and non-axial flaps transfer, axial flaps transplantation by microvascular anastomosis. Non-traumatic operating and postoperative supervision and nursing of flaps should also be paid enough attention.