Abstract: Effect of carding machine using on card sliver and yarn of polyester was studied. The card sliver and yarn were processed by respectively using gill pin taker-in and saw-tooth take-in under different speeds, and the content of short fiber and nep of the card sliver, yarn evenness, and yarn strength were tested with conventional method. The test results show that, the content of nep and short fiebr was lower when gill pin take-in was used than those of saw-tooth take-in, the quality of yarn produced by using gill pin taker-in was better than that of saw-tooth take-in as a whole, especially the parameters of yarn strength and strength CV% value. It is concluded that, the gill pin with smooth surface without edge, and small tooth-top area resulting in less fiber damage and lower nep content.