Objective:To compare the variability of midpalatal suture maturation ratio of skeletal class Ⅰ malocclusion adults between genders,among positions and vertical skeletal patterns.Methods:173 skeletal class Ⅰ malocclusion adult patients were included and divided into 6 groups according to GoGn-SN Angle and gender:dolichofacial group(male 22,female 24)with GoGn-SN＞37.7°,me-sofacial Group(male 30,female 33)with 27.2°≤GoGn-SN≤37.7° and brachyfacial group(male 33,female 31)with GoGn-SN＜27.2°.The midpalatal suture maturation ratio in the corresponding area of anterior,medial and posterior region were measured and calculated by Mimics 21.0 software,the overlap of the anterior nasopalatine canal with the measurement site was recorded.Results:In the comparison of different genders,there was a statistically significant difference between males and females in the brachyfacial an-terior region(P＜0.001).In the comparison of different positions,except the females among the anterior,middle and posterior regions in brachyfacial group(P＞0.05),there were statistical differences in the fusion degree of the other parts of the palate suture(P＜0.05),and it gradually decreased from the posterior region to the anterior region.In the comparison of different vertical skeletal pat-terns,there was no statistical difference except the difference between the mesofacial and brachyfacial and dolichofacial groups in the middle area of males(P＞0.05),and the difference was significant among brachyfacial,dolichofacial and mesofacia groups in the ante-rior area of females(P＜0.05).Rates of anterior nasopalatine duct influence measurements were statistically significant in the compari-son between dolichofacial and brachyfacial males,and between brachyfacial males and brachyfacial females(P＜0.05),the remainder was not statistically significant(P＞0.05).Conclusion:In adult patients,the palatal suture is not completely fused,and palatal mi-croimplant anchorage should be avoided in the midpalatal suture.