Objective: This study aimed to explore the development of the frontal sinus (FS) in Han people by computed tomography (CT) images and the growth pattern according to age. Materials and Methods: CT scans of 285 patients aged between 1 and 25 years were enrolled in this retrospective study. Three-dimensional (3D) reconstruction images were obtained using Mimics software, and frontal sinus dimensions (height, width, and depth) and volumes were calculated. All measurements were analyzed independently to find the relation between frontal sinus parameters and age. Results: Frontal sinus started to pneumatize around 2 years old and continually grew until 17. Two accelerated growth periods were found between 4 to 8 and 10 to 14. The volume of the left frontal sinus was statistically significantly larger than the right. Frontal sinus was bigger in males than in females, but no statistically significant difference was observed under 17 years of age. After frontal sinus reached adult levels (17 years old), there was a statistically significant difference between genders (P < 0.05), except for the width of the right frontal sinus (P = 0.085). Conclusions: This study used 3D reconstructed CT graphs to illustrate the dimensions of frontal sinus growth according to age among Han people, helping provide a reference for the diagnosis and treatment of frontal sinus disease and for further research.