A method and apparatus for bonding yarns in a process for feeding yarn from wound packages to a yarn-processing machine. The operation includes the following parts: releasing unit (1) which can release the yarns at a prescribed speed; support unit (2) which supports the yarns in a state in which a projection of the second yarn crosses the first yarn thermal fusing unit (3) which presses the yarns into contact and heats and fuses the crossed portion of the yarns; and storage unit (4) which stores a prescribed amount of yarn continuously feeding yarn to the processing machine while the yarn bonding operation is performed.