This paper presents a novel microstrip design to increase the bandwidth of spurline bandstop filter (BSF). This design combines between conventional spurline section and stepped impedance resonator (SIR) in one filter. The compact structure of bandstop filter is designed by using microstrip transmission lines at 2.4 GHz. The proposed filter has a better and wider bandwidth with S21 from 2.1 GHz to 2.64 GHz at −20 dB rejection band while the conventional spurline has a bandwidth from 2.3 GHz to 2.4 GHz. The performance of the proposed filter is simulated by Agilent ADS with a good rejection band at −80 dB.