The purpose of research is to study the influence of emotional stress on the activity of digestive enzymes in blood serum of individuals with different initial tone of the autonomic nervous system. Students' session acted as a model of emotional stress. Based on ritm-cardiografic testing according to the indicators of heart rate variability (HRV) 120 healthy young people (18-22 years old) were divided into 3 groups. Hardware-software complex "Varikard 2.51" has been applied to record the electrocardiography and heart rate variability analysis. Regulatory system tension has been selected as an indicator of autonomic balance index, that did not exceed 30 conventional units in student with vagotonia, ranged from 31 to 120 conventional units in normotonics and values from 121 conventional units characterized sympathicotonia. The interpretation of these parameters was carried out in accordance with the recommendations of the European Cardiology and North-American Society for electrophysiology, as well as the guidelines of Russian authors. The level of serum hydrolytic enzymes: 1 pepsinogen (PG 1), 2 pepsinogen (PG 2), amylase, lipase has been determined, the ratio PG 1/PG 2 was calculated. Investigations were carried out on an empty stomach in the day of workshops and during the examination session (emotional stress). The obtained data were statistically processed by variance analysis using the Student's t test. Individual variations were identified in hydrolytic activity of serum enzymes, depending on the original background level of the autonomic nervous system. It has been found that stress factors lead to opposite changes of digestive enzymes activity of blood serum, which were more pronounced in students with high baseline tone of sympatic nervous system. It has been determined that the amylolytic activity was increased in stress in all groups. A reduction in pepsinogen 2 level and lipolytic activity of blood serum has been showed in the group with simpathotony; while endocrine function of the gastric glands in the parasympatic and normotonic groups in terms of pepsinogen 2 increased.