Aim:The development of attention function in children is still not sufficiently clear. Although it is difficult to objectively assess attention function, continuous performance tests (CPT) can be used to objectively assess cognitive function along with attention. The development of cognitive and attention functions was examined in children using a CPT.Methods: A total of 541 healthy girls aged 5-12 years participated. Ten parameters were calculated: numbers of cancellations for either target stimuli (T-cancel) or non-target stimuli (N-cancel), numbers of omission errors (Omission) and commission errors (Commission), hit rate (Hit), false alarm rate (False), mean reaction time for correct response (RT), coefficient of variance for mean reaction time (CVRT), sensitivity index (d′), and lnb. Results:The parameters were divided into three types based on pattern of change. T-cancel, False, and Commission, which are related to inhibition of response, N-cancel, Hit, and Omission, which are related to inattention to stimuli, and CVRT, which is related to stability of processing time, exhibited significant change until 5 or 6 years of age. d′, which is related to ability to discriminate between target or non-target, exhibited significant change until 8 years of age. RT, which is related to processing time, exhibited significant change until 11 years of age. lnb exhibited no significant differences among age groups. Conclusions:These findings indicate that inhibition function, inattention to stimuli, and stability of processing time develop first. Discrimination ability subsequently increases based on these developments, and finally processing time is reduced.