The quasi-lumped approach is proposed to design a low-pass, a high-pass, and a band-rejection filter composing of suspended stripline (SSL) structure. The filter's operation band may possess a notch response. The notch rejection circuit is implemented from embedding a resonant slotline in the SSL's signal strip. A sample UWB filter is built from cascading the notch response circuit, the low-pass, and the high-pass filter. The two sides of suspended substrate which bearing the filter's metal patterns diversities the circuit design and might effectively reduce the circuit size. Experiment is conducted to verify the circuit design and the good agreement is observed between the measurement and simulation.