The present document provides a method for a User Equipment (UE) which activates multi-stream transmission to transmit a High Speed Dedicated Physical Control Channel (HS-DPCCH) and a UE thereof, wherein the method is applied in a multi-stream transmission system, and includes: after receiving High-Speed Physical Downlink Shared Channel (HS-PDSCH) subframes transmitted from primary and secondary serving cells, the UE which activates the multi-stream transmission transmitting a HS-DPCCH carrying jointly encoded Acknowledge/Negative Acknowledgement (ACK/NACK) and Channel Quality Indicator (CQI) after a predetermined duration by taking a later received HS-PDSCH subframe of the pair of paired HS-PDSCH subframes as a reference, wherein the predetermined duration is determined according to a timing correlation by which the UE transmits the HS-DPCCH subframe and correspondingly receives the HS-PDSCH subframe, which is specified in the 3rd Generation Partnership Project (3GPP) specification 25.211.