One of the main drawbacks of orthogonal frequency division multiplexing (OFDM) is the high peak-to-average power ratio (PAPR) of the OFDM signal. How to reduce the PAPR is the key to applying the technology of OFDM efficiently. In this paper, companding transform method is presented. The performance of the systerm BER is analysised, then PAPR is reduced by using the method through simulation. Simulation results have shown that the proposed methods are very effective and flexible to improve PAPR performance in the OFDM based on the performance of the system BER is not changed very much compare to the original system.