We are researching in various aspects of high performance computing technology including system architecture, interconnection network, system software, applications and tuning, based on the collaborative work in Center for Computational Sciences with its resources such as T2K-Tsukuba, FIRST and recent HA-PACS. The most important work recently is the system design and construction of direct communication network system for a large number of accelerators not relying on CPU for large scale parallel processing. The target applications include Lattice QCD, Astrophysics, Geo-Science (Climate) and Bioscience.