Salivary Na+,K+-excretory function was studied in senior schoolchildren-entrants during an academic year and entrance examinations. The time course of changes in the salivary levels of Na+ and K+ in entrants during an academic year was undulating. In late October that is coincident with the beginning of lessons given by tutors, the salivary content of Na+ reduced while that of K+ increased. The second peak of decreased excretion rates for Na+ and increased excretion rates for K+ and that of less Na+/K+ ratios was observed in May on the eve of entrance examinations. On the eve of the examinations, 70% were observed to have tachycardia, elevated levels of integral parameters of cardiac rhythm regulation, a considerable reduction in the concentration of Na+, and an increase in the level of K+ with less Na+/K+ ratios. The pattern of the observed changes also retained in the postexamination period. On the eve of the examinations, 30% were found to have lowered levels of integral parameters of cardiac rhythm regulation and elevated levels of Na+. After an examination, there was a reduction in Na+ excretion which did not yet achieve the initial level. The mechanisms responsible for ionic shifts in the composition of saliva during psychoemotional stress are discussed.