A total of 100 children with skeletal class Ⅱ malocclusion during the growth and development period aged 9－15 years old from 2017－2018 in the Department of Orthodontics in our hospital were selected for retrospective study. The patients’ general information （gender，height， body mass），dental arch measurement data， and X-ray cephalometric analysis data were collected， and the upper airway sagittal diameters of the children with skeletal class Ⅱ malocclusion during the growth and development period were analyzed. Through the results obtained by multiple regression analysis， the related factors affecting the size of the sagittal diameter of each segment of the upper airway were obtained.

In the laryngopharyngeal airway， compared with QCVM stages Ⅰ to Ⅱ，the laryngopharyngeal airway sagittal diameter （V-LPW） in QCVM stages Ⅱ to Ⅲ，and Ⅲ to Ⅳ were increased significantly.In the nasopharyngeal airway， compared with QCVM Ⅰ to Ⅱ stages and Ⅲ to Ⅳ stages， the PNS-UPW from stage Ⅱ to stage Ⅲ was significantly increased（P<0.05）. In the laryngopharyngeal airway， the sagittal diameter （V-LPW） was increased with the increase of the body mass index（BMI），and there were statistically significant differences between low-weight group and normal-weight group，low-weight group and overweight group （P<0.05）.The sagittal diameters （PNS-UPW and U-MPW） in low-weight group were lower than those in normal weight group （P<0.05）. In the nasopharyngeal airway， SNB and whether the patient was in QCVM stage Ⅱ were the influencing factors of the sagittal diameter PNS-UPW （P<0.05）. In the oropharyngeal airway， H-C3， ANB and soft palate length （SPL） were the influencing factors of U-MPW （P<0.05）. In the laryngopharyngeal airway， H-C3 and whether the patient was in low-weight were the influencing factors of V-LPW （P<0.05）. In the pharyngeal airway space， H-C3，ANB and whether the patient was in low-weight were the influencing factors of PAS （P<0.05）.

The sagittal diameter of the upper airway in the children with skeletal class Ⅱ malocclusion during the growth and development period is closely related to the surrounding soft and hard tissues. When formulating a clinical orthodontic treatment plan， it is necessary to comprehensively evaluate the upper airway and the patient’s own condition to avoid the iatrogenic factor-caused upper airway obstruction in the patients， and to provide a reference for the prognosis.