A pilot arrangement method in a mobile communication system in which a working frequency band is divided into a plurality of predetermined bands, and time division multiplexing is performed, the method comprising, inserting a known pilot symbol into the plurality of predetermined frequency bands at a predetermined reference interval; and inserting to arrange the known pilot symbol into at least one of the plurality of predetermined frequency bands at a smaller interval than the predetermined reference interval, wherein a pattern inserting the known pilot symbol into a at least the one of the plurality of predetermined frequency bands at the smaller interval is changed according to a predetermined pattern.