Abstract: Substrate integrated waveguide is a new planar waveguide structure with low loss, low radiation and high quality factor. In this paper, an X-band substrate integrated waveguide bandpass filter is designed, fabricated and measured. The filter can be easily integrated with other microwave planar circuits. The measured results show that the relative bandwidth is as great as 15.4％ at the operational frequency 9.75 GHz, and the return loss of the substrate integrated waveguide(SIW) band-pass filter is less than-15 dB and the insertion loss of the SIW band-pass filter is better than 1.5 dB within the passband. The simulated calculation results demonstrate that it is an accurate and efficient method.