An apparatus for the liquid flow treatment of fabrics in which a fabric is set in the form of an endless rope and the fabric and a treating liquid are circulated to effect the liquid flow treatment, the apparatus comprising a lateral cylindrical fabric reservoir tank for storing and delivering the fabric, which tank has an inclined rear portion so that the depth of the treating liquid is gradually increased in the direction of advance of the fabric, a header portion arranged above an inlet part of the tank and provided in the interior thereof with a fabric driving reel or roll for pulling up the fabric from the tank, a treating liquid jet nozzle connected to an outlet part of the header portion to generate a stream of the treating liquid, a fabric delivery tube extended from the jet nozzle to a fabric inlet part of the rear portion of the tank to deliver the fabric substantially linearly together with the treating liquid stream generated by the jet nozzle, a fabric-expanding plate which is arranged so that the width of a fabric path is expanded at an outlet part of the delivery tube, scrays arranged at the fabric outlet and inlet parts of the tank to smoothly deliver the fabric, and a treating liquid circulation passage for circulating the treating liquid while sucking the treating liquid from the bottom of the tank and supplying the treating liquid to the jet nozzle.