Abstract: To research the effect of pin carding plate on removal of impurities from card slivers,impurities tests were carried out for the card slivers under different gauges,taker-in speeds and doffer speeds using pin carding plate,saw-tooth carding plate and taker-in grid under the card taker-in by USTER AFIS single fiber tester.The results show that the ability of removing impurities of pin carding plate is worse than that of saw-tooth carding plate as a whole;the card using installing taker-in grid under taker-in is more favorable to impurities removing than that installing pin and saw-tooth carding plate.Visibie foreign matter(VFM) of the card slivers processing by saw-tooth carding plate is better than that of the card slivers processing by pin carding plate as a whole.The taker-in grid program is better than pin and saw-tooth carding plate program.The average diameter of impurities in the card slivers processed by pin carding plate is a bit larger than that of impurities in the card slivers processed by saw-tooth carding plate,while the average diameter of impurities in the card slivers processed by taker-in grid is larger than that of impurities in the card slivers processed by carding plate.