Abstract: In order to deal properly with the disinfected trays in tobacco float seedling system,the influences of disinfectant residues on tray on tobacco seed germination rate and seedling growth were tested.The results indicated that:1) the tested tray was sprayed with disinfectant solution,sealed with film for 24 hours,filled with matrix without tray washing,and seeded;the effects of different disinfectants on seedling growth,chemical components in seedling and pool water differed obviously;while there was no obvious influence on the germination percentage of coated seed;2) the trays treated with 98% trisodium phosphate at 50 g-,98% potassium permanganate at 3.3 g-,0.6% Jundujing at 5.6 ml-,40% Yubao at 6.7 ml-,2% chlorine dioxide at 10 g-allowed to be seeded without washing,while the trays treated with 7% sodium hypochlorite at 10 ml-,USA disinfectant at 20 ml-,10% chlorine dioxide powder at 2 g-and bleaching powder(30% active chlorine) at 50 g-must be washed before seeding,otherwise seedling growth will probably be inhibited.