In the present study, the concept of twist redistribution of folded yarns in a woven fabric is introduced and the reasons for the twist redistribution of folded yarns have been given. Two pure cotton woven fabrics are compared. These two fabrics have similar industrial specifications, except that one is made of 100s/2 folded yarns, the other of single 50s yarns. Using the concept of twist redistribution of folded yarns in a woven fabric and variation of yarns in a woven fabric, this paper makes use of these two fabrics to explain why 100s/2 woven fabric are becoming more and more popular or how the folded yarn fabrics are superior to the single yarn fabrics.