The demand in wireless spectrum is increased more in this 21st century. The next generation wireless networks are expected to provide multimedia services with a high QoS. The MIMO plays a key role in achieving higher spectral efficiency and preserving the reliability of the system. But in a realistic environment sharing of resources and frequency by multiple users will lead to interferences which may diminish the advantages of the system. So interference mitigation plays a major role in this context, especially for the cellular network with frequency reuse one. In this paper we focus on various system affecting interferences and the mitigating methods in MU-MIMO. It also addresses the intra cell mitigation methods like beamforming; precoding and the inter cell mitigation methods like Co-MIMO and interference alignment.