Comparative studies of subaleurone and inner endosperm cells of dry mature caryopses from 8 low-protein and 7 high-protein varieties of rye, grown in similar conditions of isolated collection, were performed by means of scanning electron microscopy technique. Low protein varieties contained starch granules differentiated in the diameter embedded in the less dense protein matrix of the wide subaluerone region. High protein varieties, besides the larger aleurone cells had in some examples wider subaluerone layer with the dense protein matrix, which was very regular and less packed with starch granules. The inner endosperm cells of high-protein caryopses contained much more dense protein matrix all around the starch granules in contrast to low-protein caryopses, which were tightly packed with starch and had only a thin layer of protein matrix around them. Comparative pronase treatment of low- and high-protein rye caryopses confirmed the above observations. No granular protein bodies in any cells, besides the aleurone ones, could be observed.