Abstract: A wideband microstrip bandpass filter (BPF) using DGS and spurline is presented. Design of the filter is based on the λ / 4 open stub bandpass filter. With using the spurline and DGS, both the bandwidth of passband and stopband are improved, besides, the harmonic suppression and return loss are greatly improved. The advanced electromagnetic microwave simulation software HFSS is used to get S-parameters. The simulation result shows that the filter has a wide 3dB fractional bandwidth which is more than 50% at the center frequency of 11.5GHz. From 1-6GHz in the first stopband, the proposed BPF has a rejection of better than 20dB and the maximum rejection level of 52dB. From 15-24GHz in the first stopband, the proposed BPF has a rejection of better than 20dB and the maximum rejection level of 46 dB. The proposed BPF has a compact structure of 12mm × 16mm.