High-redshift quasars and their host galaxies are among the most extreme systems at cosmic dawn. The stellar emission of high-redshift quasar host galaxies encodes critical information about the coevolution of SMBHs and their hosts in the early universe, which is nevertheless very challenging to detect. The unprecedented spatial resolution and infrared coverage of JWST have enabled the detection of high-redshift quasar host galaxies in the rest-frame optical for the first time. I will present the host galaxy measurements for high-redshift quasars in the Emission-line galaxies and Intergalactic Gas in the Epoch of Reionization (EIGER) project. Using deep NIRCam imaging, we successfully detect the host galaxy emission of three luminous quasars at z>~6. These quasar hosts have stellar masses of 10^10~10^11 M_sun and are among the most massive galaxies at their redshifts. The M_BH/M_star ratio of these quasars is ~10%, about 50 times larger than the local relation, which indicates an early SMBH growth compared to their host galaxies' star formation. I will also discuss the other projects in the EIGER project, including high-redshift galaxy population, cosmic reionization, and IGM properties.