For the operation of 2.45GHz ISM band, a 2x2 Multiple Input Multiple Output (MIMO) antenna system is designed and fabricated. Complementary Split Ring Resonator (CSRR) is used in the MIMO patch and loaded on its ground plane to miniaturize the single antenna element. The single patch antenna element of 14x18 mm2 is fixed in a board of the Designed MIMO antennae system measuring 100x50x0.8 mm3. The antenna is tested by measuring radiation pattern, gain, VSWR, mutual coupling and return loss. The results of the Designed antenna systems are in good agreement with the simulations. In comparison to a conventional microstrip antenna, the Designed antenna achieves a 75% reduction in the resonant frequency.