Abstract: A design method of a special class of preamble codes for OFDM systems with perfect auto-correlation performance is given in this paper.And then,based on these special preamble codes,a new frame synchronization algorithm used matched filter structure for OFDM systems was proposed.The proposed algorithm has very high efficient and can afford accurate frame synchronization time point.The computer simulation results show that the synchronization probability of the proposed algorithm is very high at low SNR.