In human motor systems neuroscience, most of the knowledge is established based on the data obtained from the adult’s brain. Yet, the knowledge about how human central motor system develops is still limited. In this talk, among various motor coordination abilities, I will focus on the timing motor control ability in 8- to 11-years old children, and provide behavioral and neuroimaging evidence that greater variance in timing control in children is likely due to the immaturity in functional and anatomical cerebro-cerebellar connections.