A circular resonator embedded with the cross structure based on the metal-insulator-metal surface plasmon polaritons (SPPs) waveguide is designed. The filter properties of this composite resonator are numerically investigated by the finite-difference time-domain method. The results show that the rotated cross structure destroys the symmetry of the resonant mode of SPPs in the empty circular cavity, which results in novel filter function of the complex resonator. The filter function of a circular resonator embedded with the cross structure depends on the rotating angle of the cross structure. Compared to θ=0° case, when the cross structure rotate to a certain angle, there is only one transmission peak in the transmission spectra. In addition, the filter properties of the composite resonator are strongly dependent on the cross structure size. These results will be helpful for designing composite filters with specific usage.