A masking sheet which is composed of a laminated composite sheet of a water-soluble film and a support made of water-soluble fibers. The masking sheet is used to prevent the migration of dye during a transfer dyeing through embroidery stitches in the production of embroidered fabrics which includes a step of piece-dyeing embroidered patterns using a transfer paper. The masking sheet is easily removed by dissolution in water. Therefore, the masking sheet is suitable for producing embroidered fabrics with good touch which have embroidery patterns with clear color and distinct profile even when the colored patterns are intricate.