This article was intended to review the works of the vapor-liquid equilibria of the nonideal multicomponent systems. The various methods were reviewed to investigate the merit of each method by literature survey. Estimation of the activity coefficient to the multicomponent system has been attempted only by using the parameters estimated from the various binary component systems. These methods are chassified into three categories; the thermodynamic approach, the molecular theory of the liquid phase and the other method. From the work of the various investigators it is apparent that Wilson's method is the best one in respect to the estimating accuracy and the broader fields of application. Some areas of application were also found for the NRTL and Wohl's methods.