The article presents the results obtained when studying the liver of rabbits who were in an experiment with the intake of silicon with drinking water at a concentration of 20 mg / l expressed in terms of silicon. The aim of the study was a comprehensive assessment of liver changes in laboratory rabbits under the conditions of the experiment with the intake of water-soluble silicon for three months. Material and methods. Rabbits were kept in a vivarium on a standard diet with free access to drinking water for three months. Animals of the control group (n = 3) received bottled drinking water, rabbits of the experimental group (n = 3) received the same water, but with the addition of sodium metasilicate enneahydrate at a concentration of 20 mg /l expressed in terms of silicon. After the animals were removed from the experiment, the liver was extracted. A part of the liver was sent to a cryostat for freezing with further preparation of fresh slices with a thickness of 10 microns and producing a Cross, Evan and Rost reaction to detect histamine luminescent structures, the other part was placed in a 10% formalin solution for subsequent paraffin embedding. Paraffin blocks were made; sections of 5 microns thick after deparaffination were stained with hematoxylin and eosin, methyl green-pyronine by Brachet method, as well as by Van Gieson method to identify connective tissue. The measurement results were considered statistically significant at p < 0.05. Results and their discussion. When stained with hematoxylin and eosin in the liver preparations of rabbits of the experimental group who received silicon with drinking water at a concentration of 20 mg/l ad libitum for three months, statistically significant increases in the average area of hepatocytes, the average area of hepatocyte nuclei, and the average diameter of sinusoidal capillaries were revealed in comparison with the preparations in the control group. An increase in the area of central veins was noted, but these changes were not statistically significant. A change in the shape of hepatocytes' nuclei was observed, which was manifested by a decrease in the shape factor of the nucleus and eccentricity and an increase in the index of the nucleus contour, as well as leukocytic infiltration of the portal tract area, formation of areas of hepatocytes' focal necrosis, proliferation of connective tissue with the formation of portal fibrosis and portoportal septa. In rabbits of the experimental group, a decrease in the DNA optical density was determined in liver histopreparations stained by Brush method in hepatocyte nuclei. We found an increase in the intensity of histamine luminescence in the luminescent granular liver cells of rabbits containing it. Conclusions. The intake of silicon at a concentration of 20 mg/l for three months results in pronounced morphological changes in the liver of rabbits.