Objective To analyze the practical effect of distalization of lower cuspiud by light-segmented archwire.Methods 17 caseswere selected. In all cases, two lower first bicuspidswere extracted and lowermolarswere designed as reinforced anchor- age. In the first half year, lower cuspids were distalized with light-segmented archwire, and lower incisors were in the physiologic drift stage. Before the treatment, three months and six months after the treatment, cephalograms and study models were recorded respectively. The data were analyzed with SPSS 10·0.Results The distance of mesiolization of the first lower molar was 1·14 mm in half a year. The distance of distalization of the lower cuspidwas 5·02 mm in half a year. No significant differencewas found in LM-MP and SN-MP angle. LI-NB angle was decreased by 9·57°. Crowding of lower incisors was transferred from -2·55 mm to 1·08 mm.Conclusion During distalization of lower cuspid by light-segmented archwire, anchorage toothwas sta- ble, lower cuspids were distalized effectively, and lower incisors drifted towards the ideal position automatically.