Barley crop grown in semiarid areas may experience water deficit especially during grain filling that makes them more dependent on stem water-soluble carbohydrates (WSC). Fructans are the most important reserved carbohydrates. A pot experiment was undertaken at Shahid Chamran University in the duration of 2010-2011 growing seasons to investigate the accumulation and loss of WSC and the activity of fructan-metabolizing enzymes under water stress in four barley (Hordeum vulgare L. ) cultivars namely Nimruz, Jonub, Nosrat and Torkaman. Cultivars were different in WSC-related traits such as WSC concentration (WSCc) at anthesis, maximum WSCc and rate of WSC accumulation in ten-day period after anthesis. Water withholding elevated WSC remobilisation efficiency. The activity of sucrose: sucrose 1-fructosyl transferase (1-SST; EC 2. 4. 1. 99) harmonized the rate of WSCc increase in cultivars. The change in fructan 1-exohydrolase (1-FEH; EC 3. 2. 1. 80) activity on the 15th day post-anthesis was along with the change in stem reserve remobilisation. Considering acid invertase (EC 3. 2. 1. 26) activity, a significant difference was observed between cultivars on the 15th day postanthesis under water-stressed conditions. Cultivars showed different manners in use of current photosynthesis and stem reserves that could be an important reason in different decreases in grain weight affected by water stress.