Left-handed metamaterials were fabricated and tested. As the first step in the test, the transmission spectra of electric resonator array and magnetic resonator array were measured, from which their respective negative parameter regions can be determined. Then, the transmission spectra of the left-handed metamaterial composed of electric and magnetic resonators were obtained. From the measured scattering parameters, effective permittivity and permeability can be retrieved. The experiment results show that there is a pass-band in the overlapping region where there is a respective stop-band for both the electric and magnetic arrays. In this pass-band, both the effective permittivity and permeability are negative, which verifies the validity of left-handed metamaterials composed of electric and magnetic resonators.