Tobacco is hygroscopic products, and the moisture content has a significant impact on its quality. The relaxation time of different cigarette samples were measured by low-field NMR techniques to study the moisture adsorption mechanism and the microstructure difference between different tobacco samples which in different water content and were observed by ESEM. T21 values are the most sensitive indicators reflected the bonding strength of water. The dominated way of tobacco absorption is through the capillary sorption while after adding a polar group such as a hydroxyl the absorption mechanism steering chemisorptions. Spongy tissue and palisade tissue is an important organizational form of tobacco, its present state and organizational structure is subjected to the combined effect of moisture and chemicals adding