The vapor-liquid equilibria for water + 2-propanol, water + 2-butanol, and water + 2-pentanol systems were measured at (523 to 573) K and (3.30 to 11.48) MPa by a flow method. The vapor-liquid equilibrium data for the water + 2-propanol system at (548 and 573) K were compared with the literature data to confirm the validity of the experimental apparatus and procedure. The phase behavior was elucidated by changing the temperatures and the carbon number of the secondary alcohols. The experimental data obtained in this work were correlated by a modified Soave-Redlich-Kwong (MSRK) equation of state. An exponent-type mixing rule was applied to the energy parameters in the equation of sate. The correlated results are in good agreement with the experimental data.