Cryogenic treatment was conducted by immersion of the melt-spun Fe₄₀Ni₃₈B₁₉Mo₃ amorphous alloy in liquid nitrogen for different times. The structures of the specimens after cryogenic treatments with different times were characterized by X-ray diffraction. The changes of coercive forces due to cryogenic treatment were investigated by B-H hysteresis loop tracer. The XRD results show that the atomic configuration of amorphous alloy becomes more disorderly due to cryogenic treatment. With the increase of the cryogenic treatment time, the free volume of amorphous alloy tends to decrease. Furthermore, the coercive force shows a non-monotonic change with the cryogenic treatment time. The coercive force after cryogenic treatment of 2 h is slightly larger than the melt-spun state, and longer time treatment results in decrease of coercive force. The coercive force is the comprehensive results of changes of chemical short-range orders and the free volume.