A novel frequency selective surface (FSS) with miniaturized element is presented, in which each periodic cell consists of a convoluted ring slot. The 2.45 GHz FSS with such structure is designed, the simulated results show that the FSS dimension is miniaturized to 0.158 λ (λ refers to the resonant wavelength of 2.45GHz). In addition, it also has good stability to oblique incidence waves for both TE and TM polarization, and there is no other resonance frequency up to 10 GHz. The influence of dimension parameters on FSS performances has been investigated. Then, dual-band FSS operated at 1.8GHz and 2.45GHz is designed. Simulated results indicate that the miniaturized FSS also provides good transmission response.