The authors gave morphometric assessment of the mucous membrane of the stomach (MMS), investigated the proliferative activity of its cells and the levels of cyclic nucleotides (cAMP and cGMP) in 60 patients with different types of chronic gastritis. A parallel study was made of the blood levels of cortisol, thyroxine, insulin, STH, and gastrin. 10 healthy persons were investigated for control. A decrease in MMS thickness, redistribution of the sizable lobes of the glandular epithelium and stroma in favor of the latter were shown in atrophic (but not superficial) gastritis. In patients with atrophic gastritis the proliferative activity of MMS cells was significantly raised, the blood levels of cortisol and gastrin were elevated, the level of thyroxine was lowered, and insulin and STH levels were normal. Marked MMS atrophy was accompanied by cAMP and cGMP insufficiency. The relationships between the morphofunctional status and the proliferative activity of MMS cells, on the one hand, and the activity of the hormonal-cyclase systems, on the other hand, were followed. The mechanisms of pathological regeneration of MMS cell elements was specified, and its importance in the morphogenesis of atrophic gastritis was confirmed.