Vapor-liquid equilibria and the saturated density for the ethylene + 2-methyl-1-propanol system at high pressures were measured at the temperatures (278.15, 283.65, and 288.15) K with a static-circulation apparatus. The experimental apparatus equipped with three Anton Paar DMA 512S vibrating-tube density meters was previously developed for measuring vapor-liquid-liquid equilibrium at high pressures. Coexisting phase composition and saturated density of each phase can be measured by means of the apparatus with a maximum temperature and pressure of 400 K and 20 MPa, respectively. The equilibrium composition and saturated density of each phase were determined by gas chromatography and vibrating-tube density meters, respectively. The experimental data were correlated with various equations of state.