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In order to evaluate heritability and gene action for some of the important quantitative traits in oriental tobacco, two genotypes, Basma 16-10 and SPT406 were crossed with Basma S. 31 cultivar, separately in 2009-2010. Parents with F1, F2, BC1 and BC2 generations were planted in a randomized complete block design with three replications. Traits such as plant height, leaf length, leaf width, leaf number, internnode number, stem diameter and yield per plant were recorded. The results obtained from analysis of variance indicated that generations mean squares were statistically significant for all traits expect for stem diameter. Therefore, generation mean analysis was performed for significant triats to estimate gene actions using Chi-square and scaling tests. The Chi-square of simple three-parametric model (additive-dominance model) was significant for studied crosses, indicating the presence of non allelic-interactions in the inheritance of these traits in oriental tobacco. Both additive and dominance genetic effects were significant for plant height, leaf length, leaf width, leaf number and internnode number. In addition, presence of high amount of dominance effect and dominance × dominance interactions suggests the importance of non-additive genetic effects for these traits in oriental tobacco. Therefore, selection for these traits in early generations can not be successful. However, additive genetic effects play an important role in the inheritance of yield, and then selection for this trait is hopeful in early generations during tobacco breeding process.