The invention provides a method and a system for indicating an idle state of a channel or reserving resources, a method and a system for indicating an idle state of an uplink channel or reserving the resources, an LTE (Long Term Evolution) terminal, an LTE base station and an LTE system. The method for indicating the idle state of the channel comprises the following steps of setting a channel monitoring sub-frame used for detecting the state of the channel in a frame structure in a time division or frequency division duplex mode; if the channel monitoring sub-frame internally detects that the channel is in the idle state, sending an indication, representing that the channel is in the idle state, to the terminal through a channel idle state signaling or a resource reservation signaling, and sending an indication, representing that the channel is occupied by the base station, to communication equipment requesting to occupy a non-authorized frequency band. According to the technical scheme, the understandings of the idle state of the channel and the reservation state of the resources by the terminal and the base station working in the non-authorized frequency band are consistent, and data based on the same core network can be seamlessly switched and transmitted in an authorized frequency band and the non-authorized frequency band.