Short-range association fibers (SAF) or U-fibers, connect adjacent gyri and constitute the majority of brain white matter. During development, SAF undergo dramatic changes in conjunction with brain network reconfiguration. How SAF reshape the brain network configuration during typical and atypical development is unknown. In this study, SAF was quantified with an index defined as normalized short-range association fibers (NSAF). We found that NSAF decreases were associated with increases in brain network efficiency in the typical developing brain from 2-7 years. Similar association were not observed in children with autism.