This chapter outlines the issues associated with the development of prefrontal cortex in children and adolescents, and describes the developmental profile of executive processes across childhood. The prefrontal cortex plays an essential role in various cognitive functions and little is known about how such neural mechanisms develop during childhood yet. To better understand this issue, we focus the literature on the development of the prefrontal cortex during early childhood, the changes in structural architecture, neural activity, and cognitive abilities. The prefrontal cortex undergoes maturation during childhood with a reduction of synaptic and neuronal density, a growth of dendrites, and an increase in white matter volume. With these neuroanatomical changes, neural networks construct appropriate for complex cognitive processing. The organization of prefrontal cortical circuitry may have been critical to the occurrence of human-specific executive and social-emotional functions, and developmental pathology in these same systems underlies many psychiatric disorders; therefore, if we understand these developmental process well, we could better analyze the development of psychiatric disorders.