Provided is a method for transmitting a data signal in a multiple-input multiple-output mobile communication system for transmitting and receiving the data signal by using a plurality of transmitting antennas and a plurality of receiving antennas, wherein when each data transmitted through the plurality of transmitting antennas is transmitted with respectively different control signals, the control signals are transmitted respectively through downlink control signal transport channels as many as the number of control signals. According to this, when information with respect to modulation methods and OVSF codes for each transmitting antenna in the MIMO system is different, it is possible to achieve efficient transmission and reception by using a method for transmitting the different information to a terminal. Furthermore, a backward compatibility between the MIMO system and the related art HSDPA system can be satisfied by using control channels similar to the control channels used in the related art HSDPA system, and the method can be unlimitedly applied to any case data is composed of one packet or of several packets.