MTR reflects the protein content such as myelin of brain. We examined the age-related MTR for common marmosets (1-18 months). Almost all regions of the brain have increased as T1 relaxation similar curve and the rate change of the MTR in each region was different. In voxel-wise analysis, MTR increase shows back-to-front maturation patterns in white matter. This pattern has observed in human studies. MTR can be a good marker to evaluate the normal brain development of common marmoset, and eventually a suitable parameter to assess brain developmental disorders for study, diagnosis, and treatments.