A reconfigurable electromagnetic band gap (REBG) structure board is analyzed and designed in this paper. It is composed of a mushroom type EBG board, varactor diodes array, chip inductors and a digitally programmable DC controlling circuit. By changing the bias voltage on the varactor diodes, the surface-wave suppressive band gap of the EBG board can be tuned from 1.86 GHz to 6.32 GHz. Furthermore, the multifunctional EBG properties with broadband, dual-band, and polarized-dependent band gap can be realized through different programming voltage control.