A device and method for cancelling code interference in a receiver of a CDMA (Code Division Multiple Access) communication system simultaneously using orthogonal codes and quasi-orthogonal codes are provided. In a receiver according to an embodiment of the present invention, a channel estimator produces a channel estimation value of a pilot channel signal spread by an orthogonal code through despeading. A quasi-orthogonal channel receiver receives a channel signal spread by a quasi-orthogonal code, despreads the channel signal, demodulates the despread channel signal by use of the channel estimation value, and provides an output. An interference estimator estimates an interference value of the pilot channel signal with the channel signal spread by the quasi-orthogonal code by obtaining a correlation value between the orthogonal code corresponding to a pilot channel and the quasi-orthogonal code corresponding to a quasi-orthogonal channel. An interference canceller cancels the estimated interference from the output of the quasi-orthogonal channel receiver.