By Koichi Hirai, Fujitsu Post-K use Arm based super computer. But there are not too many Arm based servers for HPC. Therefore we think to need to build Arm HPC Ecosystem until Post-K release. In this presentation, we describe our collaboration efforts to build the Arm HPC Ecosystem. For more info on The Linaro High Performance Computing (HPC) visit https://www.linaro.org/sig/hpc/