Aiming at the carrier synchronization sensitiveness in OFDM (orthogonal frequency division multiplexing) systems and the common synchronization method's being not suitable for data transmission in burst packet transmission mode, an improved method and a new measuring function are given. The method uses the repeatability of the training sequence to achieve carrier synchronization in time-domain. The simulation results show that, the improved method with high SNR can keep the MSE (mean square error) with the order of magnitude of 10-6, and suits for?burst packet transmission mode without the feedback of frequency domain.