Purpose: To suggest the most reliable guideline of the treatement for the supracondylar fracture in children by the comparison of the radiographic parameters between forearm supination-elbow extension and forearm pronation-elbow flexion view. Materials and Methods: A total of seventy-one patients were included in the study. Baumann, metaphyseal diaphyseal and medial epicondylar epiphyseal angle of normal elbow in extension and flexion view were compared. Finally, the results of Group I (operation with elbow extension view) and Group II (operation with elbow flexion view) were compared. Results: Intraobserver reproducibility and interobserver reliability were better in the Baumann angle with extension view and metaphyseal diaphyseal angle with flexion view. In extension view, Baumann and metaphyseal diaphyseal angle show negative correlation with carrying angle but in flexion view, only metaphyseal diaphyseal angle shows negative correlation. Baumann angle were greater in flexion view and medial epicondylar epiphyseal angle were greater in extension view. There was no statistical difference in the final results of Group I and II. Conclusion: Baumann angle was more effective in forearm supination-elbow extension view and metaphyseal diaphyseal angle was more effective in forearm pronation-elbow flexion view. The difference between elbow extension and flexion view should be considered during operation.