Abstract: The differences in morphological and physiological characters of six wheat varieties to potassium were studied using solution culture The K uptake efficient one such as 92117 and Taihe 5025 had the advantage in root length, root radius(Tab.1), uptake areas(Tab.2) , Km and Imax(Tab.3) The inefficient ones such as Jinghe 1 with low Cmin could be tolerant to low K stress There wasn't apparent relation of H+ excretion and K+ uptaked by roots (Fig.1) The morphological and physiological characters of roots could be only reference to screen K efficient uptake of wheat and kinetics parameters should be index for getting wheat with high K efficiency and tolerance to low K stress So it was better to combine the morphological characters of roots with kinetics parameters as an index