Abstract: Cembratrien-diols (CBT-diols) in tobacco is not only an important precursor substance of aroma components in tobacco leaves, but also has anti-cancer, antibacterial and other medicinal values. To reveal the genetic model and genetic effect of CBT-diols content, an F2 population was developed by crossing between the high CBT-diols content germplasm Zhijinheidiaoba (maternal parent) and low CBT-diols content germplasm Mont Clame Brun (paternal parent). Genetic analysis was carried out by using joint segregation analysis method with a mixed genetic model of major gene plus polygene.Results from genetic analysis showed that α-CBT-diol, β-CBT-diol and CBT-diols contents were controlled by 2 pairs of additive-dominant-epigenetic major genes plus additive-dominant-epigenetic polygenes (E-0). The additive effects of the two major genes were all positive, and the dominant effects were negative, and the additive and dominant effects of the first pair of major genes were stronger than those of the second pair. The heritability of the major genes of the 3 traits of CBT-diols content was 76.96%, 76.88%, and 77.55%, the polygenic inheritance rate was less than 1%. In general, the genetic effect inheritance of the 2 pairs of main genes was dominant in the three traits. Therefore, the content of CBT-diols was mainly affected by genetic effect, and the genetic effects of the major genes were the main genetic effects.