The optical transmission characteristic of colloidal photonic crystals with core @shell structure has been calculated via the finite-difference time-domain (FDTD) method. The core @shell structure has been designed using the low-dielectric Fe3O4 core and high-dielectric TiO2 shell. The results show that the behaviors of stop band can be adjusted by the effective permittivity and core @shell size ratio of materials. With the increase of permittivity, the stop bands show redshift and bandwidth increase. When the overall size of core @shell is constant, the stop bands show blueshift with the increasing core diameter, and the maximum bandwidth (Δλ/λ) reaches 33.4% when the diameter ratio between core @shell and core is 150nm: 130nm. When the core size is constant, the stop bands show redshift with the increase of the overall size of the core @shell structure. The minimum thickness of TiO2 shell that can make the stop bands appear is 3nm in the Fe3O4@TiO2 core @shell structure.