Orthogonal Frequency Division Multiplexing (OFDM) is a multicarrier modulation technique for high speed data transmission in multipath fading channels and has already been adopted in many wireless communication systems actively. One of main drawbacks associated with OFDM systems is that the output signal may have a large peak-to-average power ratio (PAPR) in the time domain, which can reduce the system efficiency. Many PAPR reduction schemes have been proposed for OFDM system to overcome this problem and one of them is the Partial Transmit Sequence (PTS) method. However, because the algorithm of PTS technique has high computational complexity, the appropriate subblock segmentation method should be employed to reduce the computational complexity of PTS method. In this thesis, the random segmentation and interleaved segmentation methods of PTS are analyzed and a combined subblock segmentation method for PTS is proposed. For analytic purposes, we derive computational complexity expressions for the proposed segmentation method and analyze the computational complexity of the proposed segmentation method compared with that of the random segmentation method. The simulation results show that the PAPR reduction performance is degraded only slightly compared with random segmentation method.