A method of transmitting uplink data by a user equipment to a base station in a wireless communication system supporting an unlicensed band, the method comprising: receiving from the base station, first downlink control information including information on a scheduling type of uplink data transmission in one or more subframes, the scheduling type including a first scheduling type and a second scheduling type; based on the first downlink control information relating to the first scheduling type: performing a channel access to the unlicensed band; and transmitting the uplink data in one or more first subframes determined based on a timing of reception of the first downlink control information, via the unlicensed band, based on the channel access to the unlicensed band; and based on the first downlink control information relating to the second scheduling type: receiving from the base station, second downlink control information triggering the uplink data transmission scheduled by the first downlink control information; performing a channel access to the unlicensed band; and transmitting the uplink data in one or more second subframes determined based on (i) a timing of reception of the second downlink control information and (ii) offset information included in the first downlink control information, via the unlicensed band, based on the channel access to the unlicensed band. receiving from the base station, first downlink control information including information on a scheduling type of uplink data transmission in one or more subframes, the scheduling type including a first scheduling type and a second scheduling type; based on the first downlink control information relating to the first scheduling type: performing a channel access to the unlicensed band; and transmitting the uplink data in one or more first subframes determined based on a timing of reception of the first downlink control information, via the unlicensed band, based on the channel access to the unlicensed band; and performing a channel access to the unlicensed band; and transmitting the uplink data in one or more first subframes determined based on a timing of reception of the first downlink control information, via the unlicensed band, based on the channel access to the unlicensed band; and based on the first downlink control information relating to the second scheduling type: receiving from the base station, second downlink control information triggering the uplink data transmission scheduled by the first downlink control information; performing a channel access to the unlicensed band; and transmitting the uplink data in one or more second subframes determined based on (i) a timing of reception of the second downlink control information and (ii) offset information included in the first downlink control information, via the unlicensed band, based on the channel access to the unlicensed band. receiving from the base station, second downlink control information triggering the uplink data transmission scheduled by the first downlink control information; performing a channel access to the unlicensed band; and transmitting the uplink data in one or more second subframes determined based on (i) a timing of reception of the second downlink control information and (ii) offset information included in the first downlink control information, via the unlicensed band, based on the channel access to the unlicensed band.