The brain matures in an organized, predetermined pattern that correlates with the functions the newborn or infant performs at various stages of development. Prior to the development of modern neuroimaging techniques, it was not possible to analyze normal brain maturation in vivo. Neuroimaging allows analysis of many aspects of brain maturation, including development of sulci , myelination, maturation of brain chemistry, changes in free water diffusion, changes in blood velocity , and changes in location specific brain activities. MRI permits highly sensitive assessment of the maturation of gray and white matter. Myelination is an important component of brain maturation because it facilitates the transmission of neural impulses through the CNS; myelination can be studied by the changes in the T1 and T2 relaxation times of the brain tissue, by assessing changes in magnetization transfer or, indirectly , by assessing changes in the degree and direction of microscopic motion of water in the brain. Imaging correlations of these changes that occur during normal brain maturation are explained in this presentation.