A direct communication method, a direct communication device, and a coordinator device using the same method are provided. The direct communication method may be adapted for direct communications between devices with multiple priorities/power upper bounds/ranges. Multiple contention/transmission slots with different power upper bounds or priorities are used as a configuration to allocate resource for the direct communication. The associated configuration acquisition is also disclosed. The direct communication method may also adopt relative periodicity of occurrence of the contention/transmission slots, and may adaptively vary the relative periodicity. The direct communication method may include an associated monitor scheme for spectrum regulation.