Abstract:Six hybrids and 13 genotypes of fluecured tobacco were used to study the genotype difference, parentoffspring correlation and heterosis of F1 generation in their nutrient characteristics. The results showed a significant difference in biomass, root/shoot ratio, contents and absorptions of nitrogen (N), phosphorus (P) and potassium (K), chlorophyll concentration, nitrate reductase (NR) activity and root activity among different genotypes of fluecured tobaccos in seedling stage. The contents of N, P and K in roots and N and K in shoot, dry matter accumulation, root activity and root/shoot ratio showed no significant correlations between F1 generation and the parents. There was a significant negative correlation between P content in shoots of F1 generation and midparent, while NR activity of F1 generation had significant positive correlation with female parent. The chlorophyll concentration of F1 generation correlated significantly with male parent, midparent and lowparent. The P and K contents in root, N content in shoot, NR activity, chlorophyll concentration, root activity, root/shoot ratio, dry matter accumulation of fluecured tobacco in seedling stage had midparent heterosis. The P content in root, NR activity, root activity, root/shoot ratio, dry matter accumulation had over highparent heterosis. The N content in root and P, K contents in shoots had no significant heterosis, but some cross combinations had midparent heterosis and over highparent heterosis.