Abstract: To investigate the dynamic variation of potassium content in flue-cured tobacco leaves, experiments were carried out with six tobacco cultivars (ND202, NC628, NC628×ND202, G28, Yizhong90 and Yunyan12) of different genotypes. The variations of K content in flue-cured tobacco leaves at the entire growth and development stages and the differences in dry-matter accumulation between different genotypes were analyzed. The results showed that in general, the K contents in flue-cured tobacco leaves slowly decreased during the growth and development stages. However, there were two rapid decrease periods at the fast growing stage and after topping separately, and a slightly increase period at the technical mature stage. Comparing with its parents, there was a delay in the K content increase and K accumulation rate reduction in tobacco leaves of F₁ generation, which had a stronger growth potential and harmonious chemical components after flue-curing. Therefore, hybridization could be considered as an effective way to promote K content in flue-cured tobacco leaves.