Objective To study the clinical effect of orthopedic-orthodontic treatment in crossbite in deciduous dentition through cephalmetric analysis. Methods 12 children with crossbite in deciduous dentition were enrolled in treatment group. Control group included 8 patients with normal deciduous dentition. Modified reverse headgear was used in each patient in the treatment group. Orthodontic force was a-bout 2. 94-4. 90 N (300-500 g) , and the direction of force was under occlusion plane for 37 degree. Each patient wore reverse headgear for 10 hour per day. Orthodontic treatment lasted for 6 months, and then orthodontic treatment began at once. Orthodontic treatment was not over until crossbite was corrected. The cephalmetric change was compared between two groups before treatment (T1) , after orthopedic treatment (T2)and after orthodontic treatment (T3). The effect of orthopedic-orthodontic treatment was analyzed in two group. Results Crossbite was corrected successfully in all patients in the treatment group. After treatment, A point moved forward by 2. 8mm, Is-FHp increased 8. 38 mm, ＜SNA increased 2. 65, incisors in mandible moved backward a little bit. All these changes were statistical different as compared with those in the control group. Conclusion Skeletal and dental deformity are improved progressively after combined orthopedic-orthodontic treatment. It is recommended to perform orthopedic-orthodontic therapy in skeletal crossbite in deciduous dentition.