Orthogonal Frequency Division Multiplexing (OFDM) is is a sophisticated multicarrier modulation technique. It's known by its robustness against frequency selective fading channels. In return, the major drawback of OFDM is the high peak-to-average power ratio (PAPR) of the transmitted signal. This feature makes the OFDM signals very sensitive to non-linearities of the High Power Amplifier (HPA). Partial transmit sequence (PTS), is one of the most attractive method to reduce the PAPR in OFDM systems. It achieves considerable PAPR reduction without distortion, but it requires an exhaustive search over all the combinations of the given phase factors, which results in a computational complexity increases exponentially with the number of partitions. We propose in this paper, a sub-optimal PTS method based on Differential Evolution optimization method (DE), reducing efficiently the computational complexity.