K326, a flue-cured tobacco variety was used to observe the effects of different Na2SeO3 concentrations (0.0, 0.1, 0.5, 1.0, 2.0, 5.0, 10.0, 20.0 mg/L) on seed germination of tobacco. The results showed that germination period of tobacco seed appeared earlier, germination speed and rate increased and sprout potential improved with the increase of selenium concentration. Sprout potential and germination rate were significant higher than those of the control, and chlorophyll content presented a falling-rising-falling trend in selenium concentration of 1.0 mg/L or above. Seedling dry weight showed no significant change when selenium concentration was below 2.0 mg/L, but decreased under selenium concentration above 2.0 mg/L. Root length of germinating seed decreased with increasing selenium concentrations. The comprehensive score in treatment with 2.0 mg/L selenium was the highest, followed by treatment with 1.0 mg/L selenium and treatment with 20.0 mg/L selenium. In the process of tobacco seedling with floating system, selenium concentration ranged between 1.0 –2.0 mg/L is favorable to tobacco seed germination.