Research on finding additional sources of vegetable protein as an alternative to soy has shown a great prospect of using lupine. The study of biological effects of flour of nonalkaloid lupine Dega variety will assess the future prospects for its use in food industry. The aim - a comparative study of protein products - soybean flour and non-alkaloid lupine flour (Dega-1 variety), added to laboratory rats' diet. Material and methods. Experiment was carried out on three groups of Wistar rats (n=30, 210±5 g) for 28 days: 1st group - rats that consumed the standard vivarium diet (control); 2nd group and 3rd group - animals, that consumed standard diet with addition of lupine flour (protein content - 42.1%) and soy flour (protein content - 50.2%), replacing 26 and 23% protein in standard diet, respectively. Results. As a result of the experiment, fluctuations in body weight of rats in 2nd group and 3rd group were observed from the 11th day; the weight gain of rats in 1st group was 7.74%, 2nd group and 3rd group - 3.32 and 2.04%. Noted changes could be explained by food adaptation of organism to the main nutrients of protein products. The blood test showed minor changes in the hematological and biochemical parameters within physiological reference values. Consumption of lupine flour led to a slight increase of leukocytes (by 14.2%) and lymphocytes (by 24.5%), an increase in the activity of certain enzymes (aspartate aminotransferase by 18.4%, alanine aminotransferase by 26.2% and lactate dehydrogenase by 21.6%, p≥0.05), while alkaline phosphatase activity decreased (14.4%, p<0.05) in comparison with control. Incorporation of soy flour into the diet of rats showed a statistically significant increase in the concentration of monocytes, eosinophils, basophils and immature cells (by 57.1% in comparison with 1st group and 83.3% in comparison with 2nd group), while relative content of granulocytes reduced (by 15.1% relative to the control). Conclusion. The inclusion of plant proteins into the rat's diet did not cause significant deviations in physiological (motor activity), biochemical, hematological parameters in experimental animals. However, the identified features in animals of the experimental groups, possibly related to biologically active substances and anti-alimentary factors in soybean and lupine, indicate the need to improve technological approaches to lupine protein products production in order to improve functional characteristics and completely remove substances that deteriorate nutrients absorption. A possible solution is lupine proteins' proteolysis, the use of various methods of fractionation, isolation and purification in combination with pretreatment to obtain protein concentrates or isolates with improved nutritional, technological and functional properties. Copyright© GEOTAR-Media Publishing Group.