We aimed to develop gait standards for gait parameters in school-aged Japanese children and assess age-related differences in gait patterns and parameters. Children aged 6-12 years (n = 424) were recruited from two elementary schools. An instrumented three-dimensional gait analysis system was used to record each child's gait kinematics, kinetics, and spatiotemporal parameters. Participants were subdivided into three age groups (Group A, 6-8 years; Group B, 9-10 years; and Group C, 11-12 years). LMS Chartmaker, version 2.54, was used to create a developmental chart for the gait pattern. The non-normalized step and stride lengths were significantly longer, and the cadence was lower in older children; however, the opposite outcome occurred when analyzing normalized data. Ankle moment differed significantly by age, and the maximum ankle moment was higher in older children than that in younger children. Furthermore, the hip and knee flexion angles during gait and the normalized spatiotemporal parameters of Japanese children aged 6-12 years differed by age and from those of children from other countries. The centile chart of the gait pattern is a useful tool for clinicians to assess developmental changes in the gait pattern and detect gait abnormalities in children.