The contribution of anisotropic hopping to magnetostriction is calcula
ted for a CoNiSiB amorphous sample. The calculations are performed for
both as-quenched and annealed samples. Partial directional ordering o
f 3d atom pairs makes magnetostriction about twice smaller after the a
nnealing, as was observed in experiment. Two-ion magnetic interaction
in amorphous alloys is concluded to be responsible for annealing-induc
ed changes of the magnetostriction lambda(s).