Abstract: To examine the differences in agronomic traits and tobacco leaf quality of K326, K326 mutant (ntcycb2) and K326 mutant (nthd9) of Nicotiana tabacum, the agronomic traits and epidermal trichome densities of the above three materials were investigated at bud stage, the contents of leaf surface chemical components of tobacco plants at bud stage and the contents of conventional chemical components and neutral aroma components of cured tobacco leaves were determined, and the sensory quality of cured tobacco leaves was evaluated. The results showed that there were no significant differences in plant height, maximum leaf length, maximum leaf width, effective leaf number, stalk circumference and internode length between K326, ntcycb2 and nthd9. Compared to K326, the density of long stalk glandulars of ntcycb2 at bud stage increased by 136.48%, the total content of cembranoid diterpenoids and sucrose esters increased by 113.75%, the content of nicotine in cured tobacco leaves decreased by 7.09%, and the content of solanone, one of neutral aroma components, increased by 101.24%. Compared to K326, tobacco leaves of nthd9 at bud stage did not have long stalk glandular trichomes, its protective trichome density increased by 1 271.88%, the total content of cembranoid diterpenoids and sucrose esters decreased by 99.92%, the content of nicotine in cured tobacco leaves decreased bv 30.22%, and the content of solanone decreased by 75.75%. Compared to K326, the sensory quality, aroma quality and quantity, and aroma component content of ntcycb2 in cured tobacco leaves increased significantly, while the aroma quality and quantity, and smoke strength of nthd9 in cured tobacco leaves decreased significantly with significantly higher smoke irritation compared to K326.