ABSTRACT 2.Interference reduction is the challenging issue in the field of cellular communication system. Due to limited frequency bandwidth and high cost, we have to reuse same frequency band in the different geographic area resulting the CCI and ACI. In this paper we study two different type of interference. In this Survey we also presented the various interference reduction methods and also discuss the reduction process of Signal to interference ratio. Using these two tools we also evaluate the performance of the Signal to interference ratio. Keywords Interference, CCI, ACI, IRT, ET, S/I ratio . 1. INTRODUCTION Interference is a major limiting factor in the performance of cellular radio System. It [1], [2] limits capacity and increase number of called dropped. As we know that our existing base station in cellular communication system are generally Omni-directional, due to this the Signal power radiated throughout the cell area results in increase of the interference and reduce SNR due to undesired users. Although sector antenna will increase capacity of system by dividing entire cell into sector but have the same problem of interface. Emerging trends of mobile communication and ever growing demand of mobile users with[7] high speed data requirements and migrating towards 4G, Co-Channel interference and multipath in urban/dense urban environment will limit the capacity of the network. In mobile communication there are several sources of interference.viz.an another mobile within the same cell, an under progress call in a neighboring cell, other BS operating in the same frequency band. Interference is more severe in the Urban Areas [4] due to greater RF noise and more number of MS and BS. Interference causes some major problems in mobile communication. As an example of this we can visualize its effect in voice channel and control channel. Interference on Voice Channel causes: -crosstalk -Noise in the background. While Interference on Control Channel causes: -missed calls. -Blocked calls. -Dropped calls. There are two major types of interference 1. Co-channel interference, (CCI) 2. Adjacent channel interference, (ACI