A method and system are provided for transmitting data in a multiple-input multiple-output (MIMO) communication system. A receiver sets the number of sub-streams of each column of a preceding matrix with respect to all precoding matrices of channels formed between the receiver and a transmitter and measures channel states with respect to sub-stream combinations whose number is equivalent to the number of set sub-streams. The receiver transmits data according to channel states to the transmitter after measuring the channel states with respect to the sub-stream combinations and antenna combinations representing sub-streams used upon data transmission of all the precoding matrices.