【Abstract】 Objective To study the mandibular rotation of adolescent angle class II division 1 malocclusions after orthopedic treatment. Methods 70 adolescent patients with angle class II division 1 malocclusions were divided into treatment group (G1)(average aged 101±23 year ) treated with activator for 12months and control group (G0) (average aged 92±41year ) used as control. The lateral cephalograms of each patients were gotten at pretreatment (T1) and posttreatment (T2) times of the study. Structure superposition method was used to analyze the relate indexes on the lateral cephalograms. Results Functional orthopedic treatment of adolescent patients with angle class II division 1 malocclusions had no effects on the mandibular rotations, but it can change the growth amount and direction of the condylar which direction became more backward and upward, while the growth amount became larger than the untreated control group. The condylar growth direction showed positive relation to mandibular total rotation and intramatrix rotation. Conclusion Orthopedic treatment of adolescent angle class II division 1 malocclusions could get good result from regulate the growth direction and amount of condylar and had no effect to the mandibular rotations.