Orthogonal Frequency Division Multiplexing (OFDM) is a optimistic and very popular modulation technique in multicarrier domain which is quite promising regarding the issues of interferences present in next generation mobile communication systems. It deployed in the area where high data rate and low latency required while efficiency will be as better as possible. The critical problem in OFDM system is maintaining low PAPR (peak to average power ratio) because it reduces the performance of system. There are several techniques which are used to overcome problem of high PAPR in OFDM modulation system. One of the techniques is Selective Mapping (SLM) which comes in distortion less criteria. In this paper analysis of PAPR reduction of an OFDM system for distortion less transmission criterion is shown. We have also used some mathematical equations to calculate and simulate its performance. Itβs also shown that SLM method grants the user a better PAPR reduction while having high complex circuitry