Abstract： Objective To study the effect of orthodontic traction treatment of impacted maxillary central inci-sors at different ages.Methods The unilateral horizontal or vertical maxillary central incisors with root cur-vature less than 90 degrees were selected as the study group and the contralateral maxillary central incisors with the same name as the control group.CBCT was used to measure and analyze the relevant research indica-tors of the root and alveolar bone of the two groups.Results At the end of treatment,the effective rate of treatment in the low age group was 93.10％,while the effective rate in the high age group was 82.76％.In terms of root length,the low age group was slightly smaller than the control group after traction treatment,but there was no significant difference(P＞0.05).The root length of teeth in the high age group was signifi-cantly shorter than that in the control group after traction treatment(P＜0.05),and the root length of buried teeth in the low age group increased significantly compared to the high age group after treatment(P＜0.05),However,the control teeth were not significantly different between the two groups(P＞0.05).There was no significant difference in alveolar bone resorption between the high and low age groups(P＞0.05),while the buried teeth had more alveolar bone resorption than the control teeth in the height of alveolar ridge resorption on the labial side.In terms of the thickness of the labiopalatine bone plate in the buried teeth,the younger group had a greater thickness of the labiopalatine bone plate after treatment(P＜0.05),while there was no significant difference in the thickness of the palatal bone plate between the two age groups(P＞0.05).Con-clusion The traction treatment of the impacted maxillary central incisor should be started as soon as possible to promote the growth and development of the root and the reconstruction of the alveolar bone,but it still can-not reach the level of the opposite homonymous tooth.