Objective To explore devising and clinical effect of ladder-shaped osteotomy and guide apparatus. Methods From February 2002 to January 2004, with the application of guide apparatus devised,the ladder-shaped osteotomy was designed and completed by bone drill and linear saw. The experiment of ladder-shaped osteotomy was carried out on a fresh bone trunk amputated. Clinically, 3 cases were replanted by shortening humerus by means of laddershapedosteotomy. The lengths of bone shortened were 3 to 7 cm. The bone length of ladder-shaped osteotomy was 2 to 3 cm. Two cases of radius defect was repaired with free fibula. The lengths of bone transplanted were 7 and 11 cm. The bone length of ladder-shaped osteotomy was 1 cm. Results It took 2 to 3 minutes to complete the laddershaped osteotomy on the two ends of bone defect. The ends of ladder-shaped osteotomy was integrated closely. All 5 cases were followedup for 10 to 16 months. All fractures healed during 14 to 20 weeks. Of 3 cases shortening humerus, the function of elbow joint was normal in 1 case, the activity range of elbow joint was 0 to 100° in 1 case,and 0 to 80° in 1 case, respectively. Of 2 cases undergoing fibula transplantation, the function of wrist and elbow joint were normal;the pronation and supination ranges of the forearm was 30° and 40° in one, 50° and 45° in the other. Conclusion With the introduction of guide apparatus, the laddershaped osteotomy by bone drill and linear saw is a recommendable procedure because of many advantages such as simple apparatus, shortcut, laborsaving and precision.