A systematic research is carried out on intermetallic NdNi5 for the hydrodesulfurization (HDS) of thiophene. The effect of calcination and presulfidation of intermetallic NdNi5 on thiophene HDS was examined and property changes of the catalyst during calcination, presulfidation, and reaction were observed by XRD, SEM, and surface area techniques. The intermetallic compound of NdNi5 is disintegrated to fine powder and recrystallized to Nd/Ni oxide and sulfide by calcination, presulfidation, and reaction. A model for the surface area increase of the catalyst during calcination, presulfidation, and reaction was proposed and the role of neodymium was explained.