Based on the model of dual-transmission line, the permittivity ε and permeability μ of artificial material can be adjusted by equivalent construction. When they are simultaneously negative, the artificial material has some fantastic electromagnetic characteristics. Because there is no double-negative materials existing in the nature world, the research on construction and applications of artificial material has widely developed all over the world. The novel unit structure of artificial material with one-dimension and two-dimension are presented, which have low-loss and wide frequency band. At last, the calculation and experiment results have proved the validity and feasibility of the construction.