The multiple-scale Reproducing Kernel Particle Method (RKPM), one of the meshless methods, is applied to the analysis of a strain localization problem. The Lagrangian RKPM formulation and explicit time integration are employed for the simulation of shear band formation in a viscoplastic material. The multiresolution study is also performed using the multiple-scale RKPM and then, an efficient high-scale component from the viewpoint of meshless method is proposed for mesh-free adaptive procedures that will be accomplished in the future.