we have proposed an open stubs loaded tapered compact microstrip resonator cell (OSL-TCMRC) for designing of the lowpass filter with wide stopband and low insertion loss. By optimization of this structure and insertion of open stubs, undesirable response and harmonics will be suppressed. In order to validate the proposed design, a lowpass filter with low insertion loss in passband and wide stopband is designed, fabricated and measured. Simulation results are compared to the experimental results and good agreement between them was achieved.