Phase equilibria data for CO2 + 1-butanol and CO2 + water + 1-butanol systems have been measured in the pressure range from 50 bar to 130 bar at 333.15, 343.15, and 353.15 X. A novel phase behavior apparatus was used for the measurements. For the CO2 + 1-butanol binary system, only vapor-liquid-phase equilibria were observed over the whole range. For the CO2 + water + 1-butanol ternary system, experimental observations were made of three single-phase regions, one vapor-liquid-liquid equilibrium region, two vapor-liquid equilibrium regions, and one liquid-liquid equilibrium region.