The amorphous NiB/SiO2 catalyst was deactivated in partial hydrogenation of cyclopentadiene (CPD) containing 1000 ppm of carbon disulfide. After the reactivity had vanished, the catalyst was almost completely recovered by sequential base-wash and H-2-sweep treatments. The base was alkaline ethanol. The results of XRD, DSC, XPS, EXAFS, IR, SEM-EDX, and H-2 uptake measurements on the regenerated amorphous catalyst were almost the same as those on original counterparts. The regeneration operation was repeated several times, but its structural and chemical properties remained.