A method for sending a sounding reference signal (SRS) of uplink channel in a time division duplex system is provided, a terminal calculates the parameters of the resource for sending an SRS in an uplink pilot time slot (UpPTS) according to the configuration information related to the sounding reference signal (SRS) of the uplink channel, the parameters include the frequency domain start position of the resource, and then the SRS is sent over the resource; wherein when the frequency domain start position of the resource is calculated, it is necessary to determine the index of the first sub-carrier in the maximum SRS bandwidth; the terminal determines the index according to the frequency domain position of one PRACH or that of more PRACHs in the uplink pilot time slots, when the PRACH includes the sub-carrier at the lower boundary of the system bandwidth, the upper boundary of the system bandwidth is used as the end position of the maximum SRS bandwidth and the start position of the maximum SRS bandwidth is calculated; and when the PRACH includes the sub-carrier at the upper boundary of the system bandwidth, the lower boundary of the system bandwidth is used as the start position of the maximum SRS bandwidth, and then the index is determined through the start position of the maximum SRS bandwidth plus the offset parameter configured for the terminal. With the sending position of the maximum SRS bandwidth in the UpPTS, which is obtained by the method of the present invention, the interference between the SRS signal and the PARCH can be avoided, and it is possible to implement the channel sounding for more bandwidth.