This research was to provide preferable ways to guide and understand children Art by scrutinizing the mechanism of visual brain activity and also understanding the development of the brain at childhood. As stated on main body of this thesis, human brain has close relationship with visual act. Every visual information conceived by human eyes is by the light. This visual information is from Retina - Optic nerves - Optic chiasm - Optic tracts - Lateral geniculate nuclei to Optic radiations and then through Primary visual cortex and again to Secondary visual cortex. Through all this process our eye can seize movements, forms, colors, and positions. Right side of brain is non-linguistic, visual, simultaneous, spatial, formative, synthetic, and naive. Left side of brain is more linguistic, ordered, timely, logical, analytic, and rational. The size of 5-year-old child? brain becomes as big as 90% of adults‘ brain, and finally, it is as big as adults’ when it becomes 10 years old. From birth to 3 years, our brain relies more on the right side of brain, from 3 to 6, it moves to the right, at 6 years, development of the left side brain is more active than the right. Understanding this brain development is deeply related to children art and art education. Also by understanding it, we could help diagnosis by looking at children art, develop new and scientific methods of children art education, For example, we can define whether the painting is by more of the left sided brain, or right sided brain. By knowing from the painting, we also can develop ways to help right side brained child or the other way around. It is possible to develop more systematical and scientific educational methods and to apply the education of children art according to the age of brain level by studying and analyzing pre released brain researches related to the art.