Method and device for transmitting data

The invention discloses a method and device for transmitting data, which are used for transmitting uplink small data by using the SGSN/MME (serving GPRS support node/mobility management entity) through the MTC-IWF (machine-type communication interworking function) entity. The method comprises the following steps: receiving the uplink small data; determining the MTC-IWF entity; and transmitting the uplink small data through the MTC-IWF entity. By using the method and the device to transmit the uplink small data by using the SGSN/MME through the MTC-IWF entity, the small data transmission path is shortened, and the consumption of network signaling resource is reduced.