Abstract Evaluation of genetic resources plays an important role in crossbreeding and seed production. In 2023, the Vietnam Tobacco Institute tested 24 tobacco genetic resources belonging to Flue-cured, Burley, and Dark and Cigar tobacco groups. The objective was to evaluate some morphological characteristics of rejuvenated tobacco gene resources and determine the correlation between some morphological characteristics of flowers and seed yield. The experiment was setted according to the sequential method by variety. Experimental results showed that Dark and Cigar tobacco varieties had the highest biological height (171 - 172.4 cm), then Flue-cured tobaccos (164.9 cm), and the lowest was Burley tobacco varieties. Tobacco varieties had leaf numbers from 17.7 - 20.2 leaves/plant, the most leaf numbers belonged to the Flue-cured and Burley tobacco varieties (20.2 leaves/plant), and a number of the fewest leaves belonged to the Cigar variety (17.7 leaves/plant). The Flue-cured tobacco varieties had the bigest leaf length, but a narrow width, 58.4 cm and 21.6 cm, respectively; the short leaf length was Cigar tobaccos (53.1 cm), but the width of leaf was large, with 27.3 cm. The weight of 1000 seeds and the germination rate of the genetic resources achieved the quality requirements. Inflorescence distribution, flower length, number of capsules/plant and off flower time affected 78.5% of seed yield. Seed yield positively correlated with the number of capsules/plant and mature time, but negatively correlated with flower length and inflorescence distribution. Experimental results are important information for crossbreeding, seed production, and selection of beneficial genotypes for production and research.