A method is presented for transmitting uplink control information in a wireless communication system supporting carrier aggregation and operating in Time Division Duplex (TDD). The method includes transmitting 4 bits (o(0), o(1), o(2), o(3)) for hybrid automatic repeat request acknowledgements (HARQ-ACKs) on a physical uplink shared channel (PUSCH). The 4 bits correspond to a first set of HARQ-ACKs associated with a first component carrier (CC) and a second set of HARQ-ACKs associated with a second CC according to a relation.