Abstract: Some quality specifications of card slivers are tested under three conditions.The short fibers,neps and trash in card sliver are checked by AFIS single fiber test system under different wind′s flow conditions.The result shows that either too large or too small wind′s flow at back plate is unfavorable to card sliver quality,and a wind′s flow about 180～240 m~³/h is advantageous under such conditions.