A method for establishing a multi-carrier HSDPA channel and method for transmitting multi-carrier downlink packet data are provided. The method for establishing a multi-carrier HSDPA channel includes: A. determining number of HSDPA channel resources of a cell; B. selecting N carriers in the cell according to the number of channel resources determined in step A, wherein the N carriers form the HSDPA channel resources; C. allocating the HSDPA channel resources to be HS-DSCHs, uplink and downlink control channels; D. allocating, by a network, an HS-DSCH to be used by a user terminal, one or more HS-SCCHs and one or more mate HS-SICHs to be monitored by the user terminal, when the user terminal initiates an HSDPA request and the request is allowed. The method may be applied to multi-carrier downlink packet data transmission, to enhance peak transmission rate of user packets, optimize the resources, thereby improving system throughput.