A new method to improve the gain of patch antenna with metamaterial composed of ring aperture lattice is presented. The influences of the number of metamaterial layers and a comparison of electromagnetic characteristics between the conventional patch antenna and the new metamaterial patch antenna are studied by using numerical simulation method. Then, a patch antenna with the metamaterial is fabricated and measured. The simulation and experimental results show that this method is effective and this structure can realize congregating the radiation energy, thus the gain of the antenna with metamaterial can greatly increase when compared with the conventional one.