Zhijie Qu is a KICP Associate Fellow at the University of Chicago, before which he obtained the PhD degree from the University of Michigan in 2021. Since his PhD, he has been working on observations and modeling of multi-phase circumgalactic medium, which is a massive baryon reservoir surrounding the galaxy. His research aims to investigate fundamental accretion and feedback processes regulating galaxy formation and evolution.The circumgalactic medium (CGM) plays a critical role in galaxy formation and evolution by mediating inflows and outflows. Recent years have seen significant progress in observations and understanding of the multiphase nature of the CGM. This talk will specifically focus on two phases: the hot phase with temperatures of log T >~ 6 and the photoionized cool phase at log T ~ 4, which have the most well-constrained physical conditions. In addition, I will introduce ongoing missions in the near future to advance our understanding of the CGM.