The (p, rho, T) properties of {(I - x(1) - x(2))H2O + x(1)CH(3)OH + X2LiBr} over a wide range of state parameters are reported for the first time. The experiments were carried out in a constant volume piezometer over a temperature range from 298.15 K to 398.15 K, at x(1) = 0.58302, x(2) = 0.07148; x(1) = 0.31791, x(2) = 0.11693; x(1) = 0.14923, x(2) = 0.05489; x(1) = 0.10425, x(2) = 0.15356; x(1) = 0.04677, x(2) = 0.16341 from atmospheric pressure up to 60 MPa. The experimental uncertainties are DeltaT = 3 mK for temperature, DeltaP = +/-5 (.) 10(-2) MPa for high pressure and DeltaP = +/-5 (.) 10(-4) MPa for atmospheric pressure, Deltarho = +/-3 (.) 10(-2) kg (.) m(-3) for density. A equation of state was derived for correlation of the experimental data of solutions.