Objective: based on the analysis of the activity of proteolytic enzymes in the peripheral blood, to elucidate the mechanisms of the formation of candidal stomatitis. Material and methods: 76 patients (the main group) with candidiasis stomatitis and 20 persons without oral pathology participated in the studies. They made up a control group. The material for the study was a blood serum of patients with candidiasis of the oral mucosa. Results: An important role of the kallikrein system, the activity of proteolytic processes and the reduction of proteolysis inhibitors in the pathogenesis of inflammation of the oral cavity initiated by candidiasis has been established. Conclusions: proteinases and their inhibitors play an important role in the pathogenesis of candidal infection of the oral mucosa. The increase in kallikrein, prekallikrein, total proteolylytic activity, cathepsin and elastase in the blood initiates the systemic level of the inflammatory process.