Abstract: To research the effect of pin carding plate on removal of neps in the card slivers,nep tests to the card slivers under different processing conditions using pin carding plate,saw-tooth carding plate and taker-in grid under the card taker-in by USTER AFIS single fiber tester were done.The results show that: 1) within a smaller gauge range,the ability of removing neps and seed coat neps(SCN) of pin carding plate is stronger;the ability of removing neps and SCN of pin carding plate and saw-tooth carding plate are better than the taker-in grid program as a whole;2) when the gauge is larger,as a whole,the ability of removing neps of sawtooth carding plate are better than pin carding plate and that of the above two kinds of carding plate are worse than taker-in grid.The ability of removing SCN of carding plate and taker-in grid are different with the change of raw materials;3) when the gauge is smaller,neps diameter in the card slivers processed by saw-tooth carding plate is a bit larger.When the gauge is larger,neps diameter in the card slivers processed by pin carding plate is a bit larger.Compared with taker-in grid,neps diameter in the card slivers processed by carding plate is a bit smaller.