A frequency spectrum coordination device and method, and a device and a method in a wireless communication system. The frequency spectrum coordination device, used for coordinating usage of shared wireless transmission resources by multiple systems, includes: an acquirement unit, configured to acquire a usage state of the shared wireless transmission resources; and an allocation unit, configured to allocate, according to the usage state, the shared wireless transmission resources for a communication device based on the influence of resource elements to be allocated of one system in multiple systems on the available resource elements of other systems in multiple systems, and the resource allocation granularity of one system is smaller than the resource allocation granularity of other systems.