A novel compact band-stop frequency selective surface (FSS) with angular and polarization stability performance for ultra-wide band (UWB) applications is presented in this paper. The designed unit cell consists of a square loop element and a crossed dipole with a ring slot element. The novel unit cell size is miniaturized to 0.047 lambda x 0.047 lambda, where lambda is free-space wavelength corresponding to the lowest frequency of the UWB band. The -3dB bandwidth of the proposed FSS is between 3.05 GHz and 10.73 GHz frequencies which covers the whole UWB band as defined by FCC. Due to compact size of unit cell, the proposed FSS has good angular stability up to 60 degrees incident angles both perpendicular (TE) and parallel (TM) polarization. The maximum resonance frequency deviation is 1.75% for TE polarization. In addition, the proposed FSS has excellent stable resonant frequency. The designed FSS is fabricated and experimental measurements are performed. There is a good consistency between numerical simulations and measurement results.