Abstract: 【OBJECTIVE】In order to study the best cultivation way of Flue-cured tobacco ,and show dynamic changes of soil available nutrient under different cultivation, according to the field experient【METHOD】the content of soil available nutrient under three treatments of natural planting, plastic mulching and straw mulching were studied in this paper. The result showed that the contents of soil available nutrients of natural planting were low becauses of temperature ,water and so on, but it accorded with the absorbing nutrient rule【RESULTS】The content of hydrolytic N of plastic mulching decreased after increased, and it disagreed with the absorbing N rule. Straw mulching could improve the contents of soil available nutrients【CONCLUSION】The content of hydrolytic N decreased smoothly after mature period. Although straw mulching was help to produce good quality Flue-cured tobacco,it should reinforce some effecttive cultivated adjustment research in order to make straw mulching become the best cultivation way to produce good quality Flue-cured tobacco.