The present description relates to a wireless communication system, and more particularly, to a method and apparatus for uplink multiple input multiple output (MIMO) transmission. A method for performing an uplink MIMO transmission according to one embodiment of the present invention comprises the following steps: transmitting, from a first subframe, a first data block and a second data block through a first HARQ process and a second HARQ process, respectively; receiving, at a second subframe, uplink scheduling control information on the first data block and control information which indicates inactivation of the second data block; setting HARQ feedback information on the second data block to an ACK state; and performing retransmission of the first data block from a third subframe on the basis of the uplink scheduling control information on the first data block. Retransmission of the second data block may not be performed until uplink scheduling control information on the second data block is received.