Dehydrins (DHN) are water-soluble lipid-associating proteins that accumulate during low-temperature and water-stress conditions, and are thought to play a protective role in freezing and drought tolerance in plants. The synthesis of the dehydrins, representing a link between environment and nuclear activity through dehydrin genes (Dhn) expression, was known to be a common response to drought in plants. The association of mRNA accumulations of Dhn genes (Dhn6, Dhn11 and Dhn13) with phenotypically diverse drought-tolerant genotypes was investigated in hull-less barley (Hordeum vulgare subsp. vulgare). Notably, differences between genotypes were observed, mainly in Dhn6 and Dhn13 gene, depending on the duration of the dehydration stress. Compared with drought-sensitive genotypes, the relative expression levels of Dhn6 gene were significantly higher in drought-tolerant lines subjected to 8 h water deficit. By control with continuative ascending accumulations in sensitive plants during drought, the highest transcript level of Dhn13 was observed in tolerant genotypes after 8 h of dehydration, and tended to descend the same levels as sensitive lines subjected to 12 h of dehydration. Based on decreased accumulations of Dhn11 during drought stress, it was concluded that Dhn11 was not up-regulated by water stress between genotypes. The observed differences in the present study may indicate an association of physiological response to water stress with differential accumulations of Dhn genes between drought-contrasting genotypes. The authors suggest different DHNs may play variable functional roles in structural protection in plants subjected to progressive water stress, associated with drought-contrasting genotypes. Key words: Dhydrin genes, quantitative reverse transcription polymerase chain reaction, water deficit, Tibetan hull-less barley