The transmission characteristics of the structure of defective rectangular ring resonator based on metal-insulator-metal waveguide were investigated in the finite difference time domain method. This structure consists of a waveguide channel and a defective rectangular ring resonator，which is parallel to the waveguide．Compared with the perfect rectangular ring resonator, the structure with defect destroys the symmetry of the resonant modes in the resonator, which results in a novel filter function of the complex resonator. The effective length of the structure depends on the size of the defect, so filtering wavelength can be tuned by adjusting the dimension of the defect. The numerical simulation results are essentially in agreement with the transmission line theory calculation results. In addition, the coupling strength between the waveguide channel and defective rectangular ring resonator is dependent on the defect location, which is useful in the control of the transmittance at filtering wavelength. Compared with the other filtering structures, our structure can realize more broadband segment filtering, effectively adjust the filtering wavelength and control the transmittance without changing the overall size. When the size of detect is chosen on a certain value, a new double degenerated mode appears, which improves the filtering properties of the structure. It has potential application in integrated optics due to its miniaturization and simple fabrication process.