Abstract: A method for estimating the velocity of the Mobile Station (MS) in Orthogonal Frequency Divisional Multiplexing (OFDM)/Orthogonal Frequency Divisional Multiplexing Access (OFDMA) system is disclosed. First, the pilots in the preamble are received by MS and the pilots in a specified symbol of the specific zone are received by MS. An auto-correlation between the received pilots in preamble and the received pilots in the specified symbol of the specific zone is calculated. The auto-correlation is the calculated with frame by frame basis, and the average auto-correlation is calculated from number of frames. Once the average auto-correlation is obtained, the velocity of MS is estimated from predetermined function according to the obtained average auto-correction.