Objective:To evaluate the effects produced by Headgear-Twin-block appliance for skeletal Class Ⅱ malocclusion. Method:One treatment group(Group R)consisted of 12 patients(8 males,4 females,mean age of 11 years 2 months)who treated with Headgear-Twin-block appliance.The other treatment group(Group T)also consisted of 12 patients(8 males,4 females,mean age of 11 years 6 months)who treated with Twin-block appliance without headgear. The control group(Group C)contained 12 patients(6 males,6 females,mean age of 10 years 8 months)giving up treatment after the examination. All the patients met the criteria as follows:(1)ANB≥4.5°;(2)Overjet≥6 mm and overbite≥3 mm;(3)Retrusive mandible. The patients of three groups were taken cephalometrics before and after the treatment or observation. Results:Compared -驻R with -驻T,SNA,U1-SN,Ls-E,Li-E,U1-Stms,U6-FHp decreased more and PP-SN,SN-MP,U6-CFH increased less,which had significantly difference (P < 0.05). Conclusion:Headgear-Twin-block appliance is effective to treat Class Ⅱ division 1 malocclusion by promoting the mandible and restraining the maxillary effectively to improve hard and soft tissue.