Epoxy urethane composites (EU) have been developed based on polyisocyanate (PIC), epoxy resin (ED-20), and sodium silicate (SS). The results of the study of the influence of the ratio of the components of the EU on their thermophysical and physicomechanical characteristics are presented. The method ofdifferential scanning calorimetry revealed thatthese systems do not have clear temperature transitions, which indicates a fairly homogeneous and rigid structure. Studies of thermal properties by the method of dynamic thermogravimetry have shown that as the amount of sodium silicate increases, the temperature of the onset of decomposition of the EU is shifted by 20 ° C towards lower temperatures. At the same time, there is a slowdown in the decomposition of epoxy urethanes (weight loss is 12-14%), due to the presence of heterocyclic isocyanurate fragments, which is inherent in its own high thermal stability. The mechanical properties of the EU, such as compressive strength, modulus of elasticity, relative compression deformation, flexural strength, and water absorption, are determined depending on the ratio of components. High mechanical properties are shown regardless of the inorganic component amount. The modulus of elasticity, strength, and relative deformation in compression is in the range of 1916.4 - 4187.6 MPa, 117.4 - 133.1 MPa, and 24.7-30.4%, respectively. The highest flexural strengths are characterized by the EC composition of the PIC / SS / ED-20 = 80/20/20, and the lowest - the EC composition of the PIC / SS / ED-20 = 70/30/20. The results of the studies show that, by changing the ratio of organic and inorganic constituents in the EC, it is possible to regulate the thermal stability and physicomechanical properties of epoxy urethane composites depending on their purpose.