Disclosed is a method for estimating a channel using a pilot signal in a wireless communication system based on multi-carrier multiple access. A transmission side generates a pilot symbol correlated with spread data symbols which is included in a spread symbol generated through a band spreading, inserts the pilot symbol into the spread symbol, and transmits the spread symbol. A reception side receives the spread symbol and detects the pilot signal by using the spread data symbols and pilot symbol included in the spread symbol. Therefore, it is possible to simultaneously obtain both the position optimization of a pilot symbol, according to a channel state such as a correlation band or correlation time (which is an advantage over the pilot-tone-based channel estimation method), and a noise reduction effect by the averaging procedure (which is an advantage over the pilot-channel-based channel estimation method), so that the accuracy of channel estimation can be improved.