Abstract: The present invention is directed to a method of caustic alkali treatment, wherein the knitted work extended in the lengthwise direction and shrunken in the widthwise direction due to the scouring (or degumming) and the bleaching treatment is, after being returned to the condition of the length and the width before the scouring (or degumming) and bleaching treatment, able to be subjected to the caustic alkali treatment and the washing treatment as it is in such a natural state as when it is knitted by a knitting machine, whereby the knitted work is never short of width as is the case with the prior art method of treatment.