Abstract: The fiber length distribution of taker-in droppings and card strips under such conditions as three kinds of pin taker-in and one kind of saw-tooth taker-in at speeds of two doffer and four taker-in level are tested with roller cotton fiber length analyzer.The results show that: 1)Fibers shorter than(13 mm) account for 41.6%～50.51% in saw-tooth taker-in droppings and 27.4%～43.48% in pin taker-in droppings.In the case of the ability of removing short fibers,the saw-tooth taker-in is better than the pin taker-in,and among the three kinds of pin taker-in,the one with small working angle is the best.2) The saw-tooth taker-in and the pin taker-in with small working angle lead to more serious damage to fibers.3)Fibers shorter than(13 mm) account for 48.23%～54.6% in saw-tooth taker-in card strips and 45.92%～58.23% in pin taker-in card strips.