Abstract: Wanmao 3, a major sun-cured tobacco cultivar in Wanyuan, Sichuan was experimented to explore the influence of different nitrogen rates and numbers of leaves on the yield, and quality, and aroma components of sun-cured red tobacco. Tobacco leaf samples from different growth periods and after curing were collected and analyzed. The results showed that with the increase of nitrogen rates and numbers of leaves, the output and yield of Wanmao 3 increased, average price and fine or medium tobacco increased first and then decreased. With the increase of nitrogen rates, the nicotine and K content increased significantly, the sugar content decreased significantly, and the aroma component contents increased significantly. And plastid pigments, phenylalanine conversion and solanone content increased significantly. This suggested that increased nitrogen rates at a reasonable level were beneficial to aroma amount in tobacco. With increased numbers of leaves, the sugar and K content increased significantly, nicotine and total nitrogen content decreased significantly. And the aroma components, neophytadiene and various of carotenoids decreased, but the phenylalanine conversion and browning product contents increased significantly. Based on comprehensive analysis, with 15 kg/667 m² of nitrogen rates and 18 leaves, tobacco leaves both have higher yield and quality, and the sensory quality is the best.