The present invention relates to an apparatus and method for estimating a channel in a MIMO wireless telecommunication system supporting the 0FDM/0FDMA. The present invention, in estimating a channel by using two or more pilots included in at least one received signal among received signals of a first channel and a second channel received through a first receiving antenna and received signals of a third channel and a fourth channel received through a second receiving antenna, determines a subchannel mapping rule respectively for the received signals of the first channel to the fourth channel, and estimates a channel with a different method according to the determined subchannel mapping rule. That is, the channel is estimated by using two or more pilots included in two or more tiles corresponding to the same subcarrier respectively, in case a subchannel rotation does not exist in the subchannel mapping rule, while the channel is estimated by using two pilots included in an individual tile, in case a subchannel rotation exists in the subchannel mapping rule.