A roller mounted onto a fabric winding machine to roll up fabric aims to solve the shortcomings of the conventional rollers that tend to cause fabric skewing during fabric rolling and are difficult to remove due to a lengthy structure. The roller of the invention has an outer diameter gradually enlarged towards two ends, and includes a first half roller and a second half roller that have respectively a first positioning portion and a second positioning portion at one end corresponding and fastenable to each other. The greater diameters at two ends allow the fabric to be rolled up on the roller without skewing. The two pieces design of the roller makes each piece shorter and removing from a bundle of rolled up fabric easier. The roller thus formed can facilitate fabric rolling and removal thereof.