A method for resource mapping of a physical downlink control channel (PDCCH), including: determining the number of resource sub-blocks to which a predefined number of enhanced control channel elements (eCCEs) correspond, according to the size of a resource sub-block in one resource block (RB); determining the number of RBs onto which the predefined number of eCCEs are needed to be mapped, according to the number of resource sub-blocks to which the predefined number of eCCEs correspond; and mapping eCCEs within the PDCCH to RBs according to the number of RBs onto which the predefined number of eCCEs are needed to be mapped; wherein locations of resource sub-blocks to which the eCCEs or the predefined number of eCCEs within the PDCCH correspond are different in each of the RBs.