The evaluation of human brain maturation in vivo is a significant problem for pediatric neurologists. MRI, especially Diffusion Tensor Imaging (DTI) and (1)H-MR Spectroscopy (MRS), can be a powerful method to solve this problem. A decrease in three eigenvalues (Δλ1 < Δλ2 ≒ Δλ3) and an increase in Fractional Anisotropy, as a function of brain maturation, was identified in the frontal and parietal white matter using DTI, which is a non-invasive imaging technique capable of providing a quantitative view of neural fibers and micro-environmental alterations during the myelination period.MRS, a powerful technique capable non-invasively quantifying N-acetyl-aspartate (NAA), a marker for neurons, glutamate (Glu), an excitatory neurotransmitter, and creatine (Cr), revealed a decrease in the Glu/Cr ratio, but found no changes to the NAA/Cr ratio with maturational changes in brain networks, such as a decrease in cortical synaptic density (refinement).Therefore, we suggest these two MRI techniques, DTI and MRS, can be used to provide direct, non-invasive information on brain maturation in vivo, which we believe will help elucidate the pathophysiology behind neurodevelopmental disorders that disrupt normal brain maturation.