Abstract: Effects of different rates of water-soluble siliceous fertilizer on yield and quality of flue-cured tobacco were studied by spraying it during rosette stage, vigorously growing stage and topping stage. The results showed that application of water-soluble silicon fertilizer improved flue-cured tobacco production, value and appearance quality, reduced the nicotine content in flue-cured tobacco leaves, coordinated chemical constituent, and improved the smoking quality of cured tobacco. The recommended spraying rate is 3 kg/hm2 for 3 times.