Abstract: The comparative experiments on growing seedling of flue-cured tobacco in plastic tray and float system were carried out in 2000-2001.The results of seedling trials in greenhouse showed that:in the float system, the seedling growth period were shorter, the effective accumulated temperature(≥ 10℃) was lower, the rates of dry matter accumulated in aerial part was higher, and the diameter and dry weight of stem were thicker and heavier;but the root system activity of seedlings was higher in the plastic tray.The results of water stress and field trials showed that:the seedlings from plastic tray were more adaptable to water stress, however, the yield and smoking quality of tobacco leaf produced by float system were higher slightly.At present, the major factors that limited the popularization of float system in the dry farming areas in the north of Chinawere lower root system activity, longer resuscitation period after transplanting and poor adaptability to water stress.