The experiment was conducted to obtain basic information on breeding of flue-cured tobacco varieties. Nine cultivars and partial diallel set of 36 F1 hybrides were grown at Taegu Experiment Station, Korea Ginseng & Tobacco Research Institute in 1983. Estimated heritability in the narrow-sense ranged from 66.21% to 94.12% for yield, leaves per plant, days to flower, leaf weight, leaf width, leaf shape, nicotine content and reducing sugar content, while that for stalk height, leaf length, midrib weight and midrib width ranged from 28.12% to 56.25%. The genotypic correlations were positive among yield, leaf weight, leaf length, leaf width, midrib weight and midrib width in the middle leaves, days to flower, nicotine content and reducing correlated with leaf length than leaf width. At the path coefficient analysis of the effect of leaf and midrib characters upon yield according to stalk position, leaf weight, leaf width and midrib width in the middle leaves, and leaf weight, and leaf width in the top leaves showed high direct effects.