In this paper,a band stop filter for two-layer frequency selective surface(FSS)at terahertz(THz)frequency with good filtering performance has been designed on high-resistivity silicon substrates.With periodic metallic resonators patterned on the silicon wafer,the designed filter can provide one typical resonant frequency for terahertz application.Simulated by finite integral time-domain method,the filter is designed to operate between 0.2 and 0.6THz with good band-stop performance.The filter exhibits typical band-stop response characteristics depending on the incident direction of electric field with respect to the designed resonator.In order to improve the roll-off rate and enlarge in-band rejection,cascaded FSS structures were adopted.Cascaded similar FSS structures exhibit better band-stop performance compared with the single designed filter.These interesting terahertz band-stop filters suggest a promising application in various fields such as biosensors,communications and national defense science and technology.