Nano- to micro-structured biodegradable poly(ε-caprolactone) nanofibrous scaffolds (PCL NFSs) were prepared by an electrospinning. Electrospinning has recently emerged as a leading technique for generating the biomimetic scaffolds for tissue engineering applications. The average diameter of the electrospun PCL NFSs ranged from 0.5 to 2 ㎛ depending on the solvent/nonsolvent mixture. PCL NFSs were irradiated using γ-ray and their mechanical properties and biodegradability were measured. In vitro/vivo degradation studies of the scaffolds as a function of the radiation dose were performed. The scaffolds were degraded more slowly in vitro than in vivo.