Jianwei Lyu is an assistant research professor at the Steward Observatory, University of Arizona and a member of JWST MIRI/NIRCam GTO teams. His major research area is the study of galaxy evolution with a focus on AGN/quasars, dust and ISM, and IR astronomy. In the first three years, JWST has made groundbreaking discoveries that transformed our view of the early Universe. In this talk, I will provide a quick review on some key findings regarding the search and characterization of the accreting supermassive black holes (SMBHs) and their host systems (including, e.g., Little Red Dots, JWST-selected high-z type-II/obscured AGNs). Notably, I will highlight some interesting results/ongoing works from our research group regarding the detection of host galaxy and AGN feedback signals in z>6 quasars, the critical investigation on the claimed cosmic evolution of the black-hole to galaxy mass ratio, and the MIRI-enabled search of high-z obscured AGNs missed by NIRCam and NIRSpec.