Abstract: Tobacco leaves maturity dicedided the structure of leave, it is great diffierence during curing with different maturity, in order to investigate structure of different maturity leave tissue, Sample of Leaves picked from middle of the stalk of K326 with maturities ranging from unripe , mature, and overripe with paraffin section on different time, research the structure of tissue of the sample during curing. The result shown that the shrinkage of leaves thickness, upper epidermis thickness, upper epidermis width, lower epidermis thickness, lower epidermis width, palisade tissue thickness and intercellur space ,spongy tissue thickness and intercellur space, is overripe leaves>mature leaves>unripe leaves during cured, the shrinkage of the overripe leaves is the most markedness, mature leaves secongdly , unripe leaves finally, whatever upper epidermis thickness, upper epidermis width , palisade tissue width and spongy tissue intercellur space of mature leaves the shrinkage ratio is up to the lower epidermis thickness, lower epidermis width, spongy tissue thickness and intercellur space.