In this letter, a dual-band Multiple Input Multiple Output (MIMO) antenna system with high isolation is presented. This design consists of two dual-band monopole antennas and neutralizing transmission line. For each antenna element, the operating frequency band covers from 2.4 GHz to 2.6 GHz and 5.2 GHz to 6 GHz. To improve the isolation between these two antenna elements spacing only 0.1225λ 0 at 2.45 GHz, a neutralization decoupling transmission line is introduced. The measured return loss results of these two antennas are better than 10-dB in operating frequency band. The measured isolation between the two antennas is better than 15 dB. The envelope correlation coefficient (ECC) is smaller than 0.01 of whole operating frequency band. The peak gain of this design is better than 2 dBi in operating bands. This configuration can be applied for Wireless local area network (WLAN), WiMAX and Bluetooth communication system.