A kind of dual-band surface plasmons (SPs) Bragg reflectors, based on metal-insulator-metal (MIM) waveguides, is proposed. By adjusting the width of the insulator layer periodically, a quasiperiodic SPs Bragg grating is achieved in the MIM waveguide structure. According to projection theory, transmission spectrum of SPs produces two band gaps, in which SPs′ propagation is prohibited under the suitable structure parameters. When inserting the defect layer of appropriate length into the structure, two SPs defect modes appear, whose center wavelengths are respectively located at around 1310 nm and 1550 nm. Because of the SPs Fabry-Perot effect, the center wavelengths of the defect modes change periodically as the change of defect layer length. The electromagnetic simulation is conducted by commercial software Comsol to verify the design.