Abstract: Application of the ryegrass with different level on the yield and quality of flue-cured tobacco was studied in Chongqing Wulong from 2006 to 2007. Results showed that the biggest leaf length, the biggest leaf width and stalk circumference of tobacco increased with the application of ryegrass. The diseases ratio decreased at the same time. After the ryegrass application the content of total nitrogen and nicotine of the flue-cured leaves decreased and the content of total sugar, reduce sugar, phenylalanines, carotenoids, browning reaction products, cembranenoids, neoplytadiene and neutral aroma total contents increased, thus made the chemical components more comfortable. The yield, production value, average price, high class leaf proportion and middle class leaf proportion of the flue-cured tobacco increased with the application of ryegrass.