Abstract: The unreasonable design of tow feeding jet in YL23 filter rod maker resulted in fluctuated tow delivering, the rod quality was influenced and the percentage of qualified rod was just about 76%.Therefore, the tow feeding system was modified:enlarging air chamber in air jacket of the jet;improving the cone-shaped funnel of tow discharge end;adding an air pressure stabilizer.After that, the rod quality was obviously improved, the percentage of qualified rod reached 99% and the efficiency of equipment was also increased.