Abstract: Uniplanar double spiral resonator is a novel left-handed unit whose existed equivalent circuit model has the disadvantages, such as the narrow frequency band and the poor fitting performance in the low frequency band. According to these problems, we proposed an improved equivalent circuit model of the uniplanar double spiral resonator and the transmission line composed of these units. The validity of these models was verified through comparing the results of full-wave simulation and the ones from the given circuit models. These circuit models can simulate the electromagnetic character of the unit and the transmission line in the frequency band from 1GHz to 5GHz. At the same time, these circuit models can predicate the frequency response of the transmission coefficient which was from the geometrical structures with different spiral rings. Therefore, the given improved circuit models can describe the primary operation principles of the corresponding structures more effectively.