The invention relates to the technical field of wireless communication, in particular to a method and a device for allocating physical resource blocks. The device and the method are used to solve the problems of increase in an error block rate of data at a receiving terminal and reduction in the resource utilization rate and user capacity of the communication system of a cell, which are caused bythe high multi-access interference generated by the method for allocating the physical resource blocks in the prior art under the influence of a smart antenna. The method of the embodiment of the invention comprises: determining the region of a cell of a terminal according to the directional angle of an incoming wave of a terminal, wherein the region is one of the plurality of regions of cells; determining the physical resource block corresponding to the terminal according to a preset mapping relationship between region identifiers and physical resource blocks; and sending the parameters of the determined physical resource block to the terminal. The method of the embodiment of the invention can reduce multi-access interference in the same cell and the error block rate of the receiving terminal and improve the resource utilization rate and user capacity of the communication system.