Method and device for allocating uplink radio resource in LTE system

The invention discloses method and device for allocating uplink radio resource in an LTE (Long Term Evolution) system. The method comprises the steps as follows: acquiring information of the number of RBs (Resource Blocks) required to be allocated by UE (user equipment) and collecting information of at least one useable and continuous UB section; selecting a UB section with the largest length as a to-be-processed UB section, and performing sliding window processing to the to-be-processed UB section to acquire a target RB section with the best channel quality, wherein the window length corresponds to the number of RBs required to be allocated by the UE; and acquiring corresponding MCS (Modulation and Coding Scheme) parameters according to the channel quality of each RB on the target RB section and sending the MCS parameters and the position information of the target RB section to the UE. After the invention is adopted, the demodulation capability of a system and the system capacity can be improved.