An apparatus and method for selecting a Space-Time Coding (STC) scheme in a Multiple-Input Multiple-Output (MIMO) system are provided. Upon generation of a data transmission event, a transmitter receives a feedback signal, encodes transmission data using an STC scheme indicated by the feedback signal, and transmits the code symbols to a receiver, and the receiver measures interference factors of available STC schemes using the received code symbols, selects an STC scheme with a smaller interference factor, and notifies the transmitter of the selected STC scheme by a feedback signal.