The original Wong - Sandier type mixing rule can only be used for two parameters cubic equation of state. By developing the excess Helmholtz free energy under a high pressure reference state and introducing suitable corresponding parameters which reflect mixing properties

Wong - Sandier type mixing rules were extended to generalized multiparameter cubic equations of state. In this work

the Modified Kumar- Starling cubic equation of state was chosen as a working equation. The method of introducing Wong - Sandier type mixing rule to generalized cubic equations of state is of great significance for extending the applications of Wong - Sandier type mixing rule where multiparameter cubic equations of state are used as working equations.