The sinking performance which is directly related to the fishing efficiency is the most important performance of the purse seine.Study on the effect of different factors on sinking performance of the tuna purse seine by model test has important significance of improving the sinking performance of purse seine.Based on the tuna purse seine model test at Qiandao Lake(Thousands Island Lake),Zhejiang Province between October 24 and 26,2009,study was conducted on the effect of leadline weight and setting speed on sinking speed of the tuna purse seine lead line by GLM model.The results showed that:(1) The lead line weight and the net setting speed had significant effect on sinking speed of lead line(P<0.05),but the interaction effect caused by the above two factors are not significant(P>0.05).(2) The sinking speed of the middle and aft parts was significantly higher at 0.795 kg/m of the leadline weight than at other level of leadline weights used.The relationship between the sinking speed of the middle part of the lead and weight of the leadline can be described as the function:V=0.114 6w 0.103 2(R²=0.871).(3) The sinking speed of lead line increased with the setting speed.The sinking speed of the forepart and aftpart was significantly higher at 1.05 m/s of the net setting speed than at other levels of net setting speed used.The relationship between the sinking speed of the middle part of the leadline and the net setting speed in pool way can be described as the following function:V=0.072 6s 0.113 8(R²=0.983).