Objective: To analyze the sagittal and vertical skeletal an d dental changes contributing to correction of Class Ⅱ division Ⅰ malocclusion and mandibular retrusion in growing children treated with Herbst appliance. Method: 27 cases of Class Ⅱ division 1 malocclusion were studied, 17 of them were treated with the domestic Herbst appliance and the other 10 case s without treatment served as the controls. Results: After 6 to 8 months (on an average of 7 months) of Herbst appliance therapy, Class II malo cclussion was corrected to Class I occlussion, overjet decreased by 7.2 mm on a n average. SNB, mandibular ramas height (Co-Go), mandibular length (Co-Pg), ma ndibular body length (Go-Pg) and the distance from Pg to OLP plane increased si gnificantly(P