The study presents the results of genetic analysis of selected morphological and physical stem characteristics determining lodging resistance in doubled haploid (DH) lines of spring barley produced from F1 hybrids of the six-rowed variety Klimek with the two-rowed variety Maresi. The DH lines, the initial forms, and F1 and F2 hybrids were tested in three-year field trials. Stem length, outside diameter and the thickness of stem walls were analyzed. Lodging rate was observed and stem material elasticity was examined using the ultrasound method. Analysis of variance was conducted for the obtained data and 6-rowed lines were compared with 2-rowed lines in terms of the investigated characteristics. Moreover, on the basis of DH lines and F1 and F2 hybrids, genetic parameters determining additive gene effects [d], dominance effects [h] and the effects of non-allelic interaction of loci in the homozygous [i] and heterozygous state [l] were estimated. For the investigated characteristics significant values of parameter [d] were found. Dominance effects turned out to be significant for stem length, stem tissue elasticity and lodging rate. Non-allelic interaction of homo- and heterozygous loci was significant for stem tissue elasticity and lodging rate. A comparison of 6-rowed and 2-rowed lines in terms of the investigated characteristics showed that 6-rowed forms exhibited smaller length and lower elasticity of stems, thinner stem walls and higher lodging rate than 2-rowed lines. It was also found that environmental factors (years) had an effect on both the mean values of the analyzed characteristics and on the difference between the 2- and 6-rowed barley lines.