[Objective] To evaluate the clinical effects of the mesial movement of the mandibular second molar, supported by gliding orthowire and mini-screw anchorage. [Methods] 17 patients, with slight malalinement but no protrusion deformity, whose mandibular first molar because of serioue caries could not extracted. After leveling the dental arch, 0.019x0.025 square arch wire was used when mini-screw anchorage was implanted. Front teeth were ligated and the mini-screw were placed into alveolar bone between the mandibular first premolar and second premolar or cuspid teeth. Then mesial movement of second molar was made by gliding orthowire arch with mini-screw and the front teeth anchorage. [Results] All patients achieved the expecting effect after 19-27 months treatment, the mandibular second molar was in preconceived position and achieved good occlusion with antagonistic molar. X-ray showed that the straight root of the mandibular second molar without nonassimilation. [Conclusion] Gliding orthowire arch and mini-screw anchorage can effectively make the mesial movement of mandibular second molar.