Abstract: In order to determine the sending time for the mobile station, a novel synchronous control mechanism for the uplink in the LTE TDD system is proposed in this paper. Firstly, the principle of synchronous control is introduced. Secondly, according to the information used to estimate the channel status, the initial, peak and end position of impulse response is detected reasonably; Moreover, the method for controlling the synchronous of uplink is proposed. Results show the effectiveness of the mechanism under scenarios with different velocity and the degree of signal to noise, additionally, the ISI induced by the inaccurate timing can be avoided.