〔Abstract〕 Objective To measure the anatomical parameters of the first maxillary molars in children of different age groups and evaluate the age-related changes in dental crowns. Methods A retrospective analysis was conducted on cone beam computed tomography(CBCT) images of 4-8-year-old children. NNT software was used to analyze multiple important indicators of maxillary first molar. Results A total of 308 first maxillary molars, including 154 pediatric patients, were evaluated in this study. The thickness of the pulp apex H1(left,P=0.01; right,P=0.02) and the thickness of the pulp chamber floor H3(left and rightP<0.01) were positively correlated with age, while the height of the pulp cavity H2(left and rightP<0.01) and the height of the palate tip D1(leftP=0.003, rightP=0.002) showed a negative correlation with age. There was no significant correlation between the height of the buccal tip and age(P>0.05). There were significant differences in H1 and H3 between the 4-year-old and 5-year-old age groups between the 8-year-old age group(P<0.05), as well as significant differences in H2 and D1 between the 4-year-old and 5-year-old between the 6-year-old, 7-year-old and 8-year-old age groups(P<0.05). Conclusion The age-related changes in the crowns of the first maxillary molars are important references for the clinical treatment, and can be accurately measured through CBCT data.