SUMMARYChanges in sugar content during water stress and recovery were examined in leaves of two varieties of durum wheat {Triticum durum). The drought-resistant Mohamed Ben Bachir (MBB) from Algeria and the droughtsensitive European variety Capdur differed in the time and type of sugar increase during water stress. Glucose accumulated at a rate closely corresponding with decreasing water potential but more rapidly and to a higher concentration in MBB than in Capdur. Sucrose content correlated less well than that of monosaccharides with changes in water potential. Glucose and, to a lesser extent, fructose appeared to play an important role during water stress and to be more sensitive indicators of the degree of stress and of potential tolerance than proline which increased later and to the same extent in both varieties. After rewatering, the amounts of accumulated solutes in leaves of both types fell quickly to normal, coincident with relatively rapid growth.