Capacity and electric resistance of lipid membranes composed of lecithin and cholesterol were determined. The components were chosen for the study because they were present in biological membranes. Capacitance of the lecithin and cholesterol membranes amounts to 0.38 and 0.61 μF/cm2, and resistance to 1.44xl04 and 2.12x 106 Ω cm2, respectively. A 1:1 complex appears as a result of lecithin-cholesterol membrane formation. Parameters of the membrane formed of the lecithin-cholesterol complex were determined: surface concentration (Γ3), capacitance (C3), and conductance (R 31), as well as the stability constant (K) of the complex. The mean values of those magnitudes are as follows: 4.265xl0-6 mol/m2, 0.54 μF/cm2, 1.381xl0-6 Ω-1 cm-2 and 3.748x107, respectively.