Method and apparatus for transmitting/receiving an uplink pilot used for channel estimation and measurement of an uplink in an FDMA system. Pilot symbols are transmitted with different frequency mapping patterns in first and second pilot symbol intervals of one time slot interval including data symbol intervals and the inconsecutive first and second pilot symbol intervals which have a shorter length than the data symbol intervals. As a result, interpolation of a frequency domain during channel estimation is not necessary, and can correctly obtain channel-estimated values of a frequency at which data is transmitted, in a fast time-varying channel environment.