Abstract: Objective To investigate the clinical effect of percutaneous cross Kirschner wire internal fixation for children with Gartland type Ⅲ humeral supracondylar fracture. 
Methods A total of 149 children with Gartland type Ⅲ humeral supracondylar fracture were retrospecitvely analyzed, and divided into internal fixation group (n=76) and external fixation group (n
=73) according to different treatment regimens. The internal fixation group was treated with percutaneous cross Kirschner wire internal fixation, and the external fixation group received plaster or small splint external fixation. At 6 weeks after operation, the elbow joint range of motion (ROM) and lifting angle of the two groups were compared. They were followed up for 6 months after operation. The Flynn elbow scoring standard was used to evaluate the excellent and good rates of the two groups at 6 months after operation. The fracture healing time, incidence of cubitus varus deformity and overall incidence of poor prognosis were observed in the two groups, and the Baumann Angle was measured before operation, after plaster removal and at the last follow-up. 
Results At 6 weeks after operation, the improvement of elbow joint ROM and lifting angle in the internal fixation group was significantly better than that in the external fixation group (P＜0.05). At 6 months after operation, the excellent and good rate of Flynn elbow score in the internal fixation group was significantly higher than that in the external fixation group (P＜0.05). Baumann Angle measured in the internal fixation group after plaster removal and at the last follow-up was obviously lower than that in the external fixation group (P＜0.05). And the fracture healing time in the internal fixation group was distinctly shorter than that of the external fixation group (P＜0.05). The incidence of cubitus varus deformity and the total incidence of poor prognosis in the internal fixation group were visibly lower than those in the external fixation group (P＜0.05). 
Conclusion Percutaneous cross Kirschner wire internal fixation in the treatment of children with Gartland type Ⅲ humeral supracondylar fracture has a definite clinical effect, which can effectively improve the prognosis of children and is conductive to the early recovery of elbow joint function. 

Key words: humeral fractures, fracture fixation, internal, child ,