As NOx emission regulation is getting reinforced, NOx removal system become more important. Among various DeNOx technology, NH₃-SCR(Selective Catalytic Reduction) is regarded as the most efficient technology. Cu-SSZ-13 zeolite catalyst is one of the most powerful SCR catalysts because of its high activity and stability. Cu ion which is the active site of Cu-SSZ-13 has mobility in the SSZ-13 cage which is important characteristics for NH₃-SCR reaction. For proving Cu ion mobility, we compare two catalysts, one is mixture of Cu-SSZ-13 and H-SSZ-13 with mortar (PM-C), the other is mixture of granule (PM-L). In the PM-C, Cu ion can move from Cu-SSZ-13 to H-SSZ-13 because each particles contact directly. However, in the PM-L sample, Cu ion can not move to H-SSZ-13 because particles were separated. By using various characterization tools, we demontrated different characteristics of the catalysts, which indicates that interparticle migration of Cu ions is possible in the Cu-SSZ-13.