Objective: The aim of this study was to investigate the developmental trajectories of attention, short-term memory, and working memory in school-aged children using a 10min test battery of cognitive function. Methods: Participants comprised 144 typically developing children (TDC) aged 7-12years and 24 healthy adults, divided according to age into seven groups (12 males and 12 females for each age group). Participants were assessed using CogHealth, which is a computer-based measure composed of five tasks. We measured attention, short-term memory, and working memory (WM) with visual stimulation. Each task was analyzed for age-related differences in reaction time and accuracy rate. Results: Attention tasks were faster in stages from the age of 7-10years. Accuracy rate of short-term memory gradually increased from 12years of age and suddenly increased and continued to increase at 22years of age. Accuracy rate of working memory increased until 12years of age. Correlations were found between the ages and reaction time, and between ages and accuracy rate of the tasks. Conclusion: These results indicate that there were rapid improvements in attention, short-term memory, and WM performance between 7 and 10years of age followed by gradual improvement until 12years of age. Increase in short-term memory continued until 22years of age. In our experience CogHealth was an easy and useful measure for the evaluation of cognitive function in school-age children.