To provide an apparatus for retaining a weft tension for an air-jet loom, capable of retaining a high tension by a small amount of air in the apparatus which introduces the tip of a weft into a stretch pipe and retains a weft tension.

A valve body which is brought into contact with an opening edge of an introduction opening when advanced and is separated from the rim of the introduction opening when retreated is installed inside the introduction opening of the stretch pipe. The valve body closes the introduction opening by its own weight or an inertial force of a beating up movement. The valve body is opened by an air pressure or an inertial force and led into the stretch pipe by an air jet from a weft introduction nozzle. The tip of the weft led in the pipe is held by the valve body to retain a weft tension. When the holding force is insufficient, holding air is sent from the back of the valve body.