A new type of terahertz band-stop filter is presented.The filter consists of two parallel metallic plates with rectangular groove arrays on their inside surfaces.Surface plasmon polaritons controlled entirely by the surface geometry can be excited in a metallic periodical surface when terahertz wave is injected.The finite element method simulation results show that the fundamental wave guide mode of the parallel metallic plates is changed into surface plasmon wave mode，and a band gap between this mode and other wave guide modes is produced.The band-stop filtering functionality is realized by rejecting all frequencies in the gap.Transmission spectra also show zero transmission within the band gap region.By slightly shifting one of the parallel plates，the structure can be improved，it makes the passband between this band-stop and higher frequency band-stop to increase，and satisfy the demand of band-stop filter.By varying the distance of two plates，groove width and groove depth，the band-stop with different filtering bandwidth and different center frequency can be achieved.