I will provide a brief overview of spectroscopic studies with Subaru to investigate the early chemical evolution of the Galaxy in the past decade and current observing projects. We have been conducting high-resolution follow-up spectroscopy for candidates metal-poor stars discovered by large spectroscopic surveys (HK, Hamburg/ESO, SDSS, and LAMOST). Such studies have been revealing the nature of first generation stars, formation of carbon-enhanced stars, individual nucleosynthetic processes, and formation of old components of the Milky Way. I will report the latest results obtained by the collaboration of LAMOST and Subaru.