A data stream transmitting and receiving method and apparatus guaranteeing quality of service (QoS), in which the data stream transmitting method includes obtaining information regarding a link characteristic change of a mobile node, which occurs due to a handover of the mobile node between heterogeneous links, and transmitting the data stream to the mobile node based on the obtained information. Accordingly, even when the handover of the mobile node between heterogeneous links is performed, QoS of the data stream can be guaranteed.