The discovery of the Higgs boson in 2012 at the Large Hadron Collider (LHC) marked a breakthrough in particle physics and deepened our understanding of the fundamental structure of matter. Comprehensive understanding of the Higgs boson requires precision measurements of its properties beyond the ultimate reach of the (HL-)LHC, for which a new accelerator complex is required. The relative lightness of the Higgs boson makes the Circular Electron Positron Collider (CEPC) technologically feasible as a Higgs factory. The CEPC, featuring a circumference of 50 - 100 km, can operate at the center-of-mass energy of 240 - 250 GeV with a design luminosity of 2×1034 cm-2s-1 and may provide 2 interaction points for experiments. The CEPC can also operate at the Z pole and the WW threshold (91/160 GeV) to allow for refined measurement of the standard model parameters. The machine is upgradable to the Super Proton-Proton Collider (SPPC) in the future. This workshop aims at exploring the full physics potential of the machine and establishing a strong physics case for the CEPC project. The design of the accelerator and the detector will also be discussed.