Traumatic brain injury (TBI) is one of the leading causes of death and disability in children and adolescents. Young TBI patients suffer from gross motor deficits, such as postural control deficits, which can severely compromise their daily life activities. Training programs have shown behavioral improvement; evidence of changes in WM morphology, however, has not been clear. We employ a fixel-based analysis (FBA) to investigate whether balance training results in significant changes of WM organization across whole brain in young TBI patients over time. Our results have shown that balance training induced signigicant macrostructural white matter changes (i.e. log-FC & FDC).