The present invention discloses a synchronizing or desynchronizing state reporting method for downlinks of physical layers, which includes steps below: In an initial synchronizing phase, a physical layer judges whether initial synchronizing conditions are met and then reports synchronizing state information of downlinks to a senior layer of protocol to enter into a synchronizing state. The protocol approves downlinks to create initial synchronization according to state information reported by the physical layer. In synchronizing state, the physical layer verifies whether desynchronizing conditions are met, the physical layer reports desynchronizing state information of downlinks to the senior layer of protocol. In desynchronizing state, the physical layer verifies the synchronizing condition is satisfied and reports synchronizing state information of downlinks to the senior layer of protocol to enter into the synchronizing state. The present invention can reduce remarkably synchronizing and desynchronizing message volume reported by the physical layer, save system signaling consumption and improve system efficiency.