Characterization of a metamaterial based on an S-Shaped resonator and a feeding transmission line using a new measurement technique is studied in this paper. First, the metamaterial is designed and simulated using conventional methods. Then, it is fabricated on microstrip and excited by using a microstrip transmission feedline. Measurements were carried out using a vector network analyzer by (SubMiniature version A) SMA coaxial terminations without needing any waveguide transmission lines. For both simulated and measured results, the effective constitutive parameters are retrieved and analyzed. Results show the practicality and feasibility of the proposed measurement method in the characterization of metamaterials for microstrip based microwave circuit applications.