Phase transformation behavior in Fe₇₇Nd_4.5B_18.5 metallic glass during electron irradiation and thermal annealing was investigated. Crystallization from glassy phase during thermal annealing occurred in multi-stages forming α-Fe and several intermetallic compounds. Electron irradiation induced crystallization occurred at 298 K and nanostructure composed of α-Fe, Nd₂Fe₁₄B and Fe₁₇B₂ precipitates embedded in amorphous matrix was formed. The electron irradiation induced crystallization behavior was discussed by atomic displacement due to electron knock-on effect and atomic diffusion via free volume in amorphous phase.