PURPOSE: To provide the subject method comprising such a practice that an entangling jet is set up on a single vacuum string-up gun and made to act on a plurality of spinning positions to eliminate the need to provide entangling jets for joining yarns on each yarn-spinning position.

CONSTITUTION: This method comprises the following practice: an air entangling jet 3 is joined via a support plate 4 to a string-up gun 5; one end of a yarn 1 is threaded via a slot 7 through a yarn channel 8, inserted into the yarn inlet 9 of the gun 5, and withdrawn into a waste yarn recovery unit by the aid of compressed air stream; in this state, a travel yarn 2 is threaded through the slot 7, a compressed air is then allowed to run to the entangling jet 3 by releasing a pneumatic switch 12 to effect mutual entanglement of the respective filaments of the yarns 1 and 2; and then, the yarn 1 is pulled by the yarn 2 and broken, or cut down by a cutting machine 14.