A wideband strong-directivity patch antenna is designed based on the metamaterial concept on the ground plane and the Yagi antenna concept of reflector and director. Due to the fact that the effective medium parameters of substrate of antenna are affected by the left-hand characteristics, the wave propagation direction of antenna is changed, which induces the strongest radiation in horizontal direction rather than the vertical direction of the conventional patch antenna. The reflector and director induce a directivity of the radiation. The simulation results show that the relative bandwidth of the designed antenna is 65.3% (6.9-13.6 GHz), the return loss is less than -10 dB, and the average gain is over 4.4 dBi in the operating range. Experimental results are in good agreement with the simulation results.