This standard stipulates the measurement method of the unit area mass and down content (covering) of pile fabrics, and provides the index expression method for the three states of standard state, dry state and public moisture regain. This standard applies to velvet fabrics with pile and ground tissue (base fabric) structures, such as plush, camel hair, artificial fur, velvet, woven (cut) velvet, floor (wall) carpets, etc. This standard does not apply to brushed, sanded and other raised fabrics.