A method and a device for notifying channel occupation time, a base station and a user equipment. The method which applies to a base station includes: in an unlicensed spectrum, performing LBT and channel access; and when a channel is accessed successfully, sending a time slot format information which indicates one or more time slots of one or more cells to a UE through a PDCCH. The method which applies to a user equipment includes: in an unlicensed spectrum, receiving time slot format information, sent by a base station via a PDCCH after channel access is successfully completed, indicating one or more time slots of one or more cells; acquiring channel occupation information and channel release information according to the time slot format information; and according to the channel occupation information and the channel release information, performing downlink reception, uplink transmission or channel access in symbols of each time slot.