Dr. Suoqing Ji is a research professor at Shanghai Astronomical Observatory, CAS. After obtaining his Ph.D. in physics from University of California Santa Barbara in 2018, he moved to Caltech as a Sherman Fairchild fellow in theoretical astrophysics from 2018 to 2021. His research interests include magnetohydrodynamics, turbulence, hydrodynamic and thermal instabilities, cosmic rays, etc., and their application in galaxy formation, the circumgalactic medium and stellar physics.Multiphase gas structure is ubiquitous in our universe. Recent observations suggest that large quantities of cool (10^4 K) gas are detected in the circumgalactic medium (CGM) of galaxy halos, which extends up to a few times of galactic virial radius. In addition, warm gas at a few 10^5 K are found to be tightly associated with the star-forming galaxies, but not the quenched ones. However, the origin and fate of such multiphase gas still remain unclear. In this talk, I will discusses how magnetic fields, turbulent mixing layers and cosmic rays can play a crucial role on the formation and stability of the multiphase CGM.