A new timing synchronization method for OFDM systems based on repeated-conjugated-symmetric preamble was proposed. The proposed timing method utilized delayed correlation and symmetric correlation to search the first tap of multipah channel with the fixed threshold after the peak position of timing metric was detected. Theoretic analysis shows that the proposed method can achieve good performance of timing synchronization. Simulation results in static multipath channel and 6-path channel for typical urban show that the proposed method prevents the timing synchronization from moving backward and achieves more accurate timing result than conventional timing synchronization method based on conjugated-symmetric timing metric.