We aimed to study the influence of soil water deficit on gas exchange parameters, relative water content, photosynthetic pigment contents of flag leaf, as well as on assimilation area and dry matter of leaves, stem, spike and grain yield of durum and bread wheat genotypes in the 2014-2015 growing season. Water stress caused reduction of photosynthesis rate, stomatal conductance, transpiration rate, an increase of intercellular CO2 concentration. Water stress severely affected on relative water content, Chl a, b and Car (x+c) content, assimilation area formation and dry matter accumulation of sensitive wheat genotypes.