To provide a method for controlling the delivery of warp yarns in a loom, without loading an electric source shut off-detecting circuit or a back up battery, capable of preserving the wound diameter of the warp yarn wound on a warp yarn delivery beam so as to improve the productivity and operation property.

This loom is equipped with a warp yarn-delivering beam 9 wound with the warp yarn V supplied to the loom, a delivery motor 10 for rotary driving the warp yarn-delivery beam 9 and an EEPROM 42b memorizing the wound diameter of the warp yarn. The controller 7 calculates the wound diameter in accordance with the delivering movement of the warp yarn with a wound diameter-calculating part 41, and memorizing the warp yarn wound diameter calculated by the winding diameter-calculating part 41 at each of the stops of a delivery motor 10 with the EEPROM 42b.