Abstract: The experiments of different fertilizing methods and different proportions of NO₃^--N and NH₄⁺-N on tobacco cv.G80 were conducted.The results showed that 1) the dry weight of root was reduced with the increase of NO₃^--N proportion at fast growing stage, and there was no obvious rule that the dry weight was affected by nitrogen proportions at harvesting stage;and 2) the leaf area and root dry weight of tobacco fertilized with narrow strip method were bigger and heavier than that of tobacco fertilized with other methods and that of tobacco fertilized with dust method were the least.Nitrogen forms had a little effect on microbe quantity, which was heavier affected by fertilization methods.