A utilization method and apparatus for guard band, used under the premise that side-channel interference is suppressed when a time division duplex (TDD) system and a frequency division duplex (FDD) system coexist, utilizes guard band effectively and increases utilization rate of mobile communication spectrum resources. The utilization method for guard band comprises: a first base station in a TDD system allocates a first frequency resource within an uplink guard band to a first user equipment and issues resource scheduling information (S1001); the first base station receives the uplink data carried in uplink time units on the first frequency resource, which is sent by the first user equipment according to the resource scheduling information (S 1002); the first base station carries the downlink data in downlink time units and sends the downlink data to the first user equipment on a second frequency resource, the second frequency resource comprises frequency resource in a downlink guard band and/or frequency resource in a TDD band (S1003).