A method for HARQ reordering in Enhanced Uplink Dedicated Channel of WCDMA system includes following steps: locating the soft combination buffer in the Node B and the reordering buffer in the SRNC; locating the HARQ entity in the Node B; locating the reordering queue distribution entity, the reordering entity and the disassembly entity in the SRNC. This invention adopts the separation technology of the soft combination buffer and the reordering buffer, the separation model can not only ensure the diversity gain, but also reduce the receiving delay and save the buffer space. Three mechanisms (timer mechanism, window mechanism and SBI mechanism) are proposed to prevent the blocking of the reordering buffer, which degrades the blocking to the least level, improves the receiving efficiency and the system performance. Aiming at the SBI mechanism, the invention proposes the new DCH data frame structure on the Iub interface and the Iur interface.