Multigrid is a scalable method for solving linear equations and for preconditioning of Krylov iterative linear solvers, and is especially suitable for solving large-scale problems. Multigrid method is expected to be one of powerful tools on post-peta/exa-scale systems. In this talk, speaker shows recent progress of his research in parallel multigrid methods using OpenMP/MPI hybrid parallel programming models with up to 8,192 cores of T2K/Tokyo, Cray XE6, and Fujitsu FX10. Several technical issues towards post-peta/exa-scale systems will be also discussed. Finally, some on-going works related to "ppOpen-HPC" project funded by JST/CREST will be introduced.