In Yongzhou of Hunan, with fixed position plot trials, straw mulching, film mulching, no mulching and no returning had been compared for series three years. The result showed that, two ways of straw returned to field improved the structure propelty of soil, yet the effect of treatment with straw mulching on soil structure property was better than the treatment with straw returned to field directly. After the rosette stage of tobacco, the temperature - humidity change range of soil was little. However, the temperature- humidity change range of soil was great and maked against growth of flue - cured tobacco with else treatment during whole procreating stage. The quantity and quality of tobacco was better with straw mulching.