Abstract: Through observing the tissue structure change of tobacco leaves, we can infer the effect of specific fertilization and select an optimal fertilization treatment. In this study, the tissue structure of‘K326’tobacco leaves was observed and compared by using the method of paraffin section. The results showed that different fertilization treatments had significant effect on the thickness of the upper and lower epidermis, the thickness of the palisade, the thickness of spongy tissue, the tissue ratio of the palisade tissue and spongy tissue, etc. Among them, treatment L2 (pure nitrogen 112.5 kg/hm2) had the maximum thickness of palisade tissue, while L6 (the medium potassium treatment, N:P:K=1:1:2.5) had the least; spongy tissue and leaf thickness were the maximum under treatment L1 (green manure plus pure nitrogen 75 kg/hm2), and the minimum was under L4 (no fertilization); the thickness of cells’epidermal under L1 was the largest, but was the minimum under L4; the tissue ratio was the maximum under L7 treatment that had no K (N:P:K=1:1:0) and was the minimum under L3 treatment(application of Chinese trumpet creeper, pure N 75 kg/hm2, pure N measure was 1.5 kg). The results showed that the tissue structure development of‘K326’tobacco leaves under treatment L3 was the most complete, the interstitial space was moderate, the elasticity was good, and the quality was the best, while the tissue structure development under treatment L5 with high potassium (N:P:K=1:1:5) was more complete than that under treatment L6 and L7. We suggest that in production, green manure should be applied with chemical fertilizer, and high potassium (N:P:K=1:1:5) treatment should be recommended to facilitate the full maturity of tobacco leaves, but this treatment needs the postponing of the picking time.