The physical development of elementary school-age children is the growth of the body and brain, the stability of sensory capacities, motor skills, and health. Elementary-age children who develop their abilities increase in various ways, especially those related to their physical development. Physically, children at basic age have their own characteristics that are different from their physical conditions before and after. The characteristics of physical development need to be studied and understood by teachers and parents because they will have a certain influence on the implementation of education. In this case, children's activities, including learning activities and other mental activities, will be greatly influenced by their physical condition. In addition, it is also believed that the physical growth of children can have an influence on the development of the child's personality as a whole. There are several things that will be discussed in this paper, including: the concept of physical development of elementary school age children, physical characteristics of elementary school age children, and brain development of elementary school age children.