Abstract: A composite metmaterial was designed in this paper, it has characteristics of wide bandwidth and low operation frequency, which is lower than 4GHz. Low reflection in certain bandwidth was obtained by simulation and experiment, which was realized by using equivalent circuit analogue method combined with Genetic Algorithm （GA）. The - 10dB reflection coefficient in 2 - 3GHz was realized by embedding FSS structure in the composite metmaterial, the total thickness is 5cm, and good measured result was achieved.