We have developed an evaluation system for the motion of pronation and supination of the forearm. This eval- uation system is a simple and portable system using wireless acceleration and angular velocity sensors. The motion of pro- nation and supination is one of soft neurological signs. This motion used as diagnosis methods of ADHD and cerebellar ataxia. There is a possibility that can be helpful to diagnosis of attention deficit hyperactivity disorder (ADHD), cerebellar ataxia, Parkinson's disease, etc. We could obtain reference curves of the neuromotor development for elementary school children (children aged 7-12) using our developed evaluation system. In this paper, we investigated changes in neuromotor function associated with aging. We measured the motion of pronation and supination of the forearm of 243 healthy sub- jects (subjects aged 21-90) and could obtain aging curves of the neuromotor function. Measured results showed that aging curves of the neuromotor function decreased between 21 and 90 years old.