Total vapour pressure measurements made by a modified static method for the binary systems of benzene, toluene, ethylbenzene and p-xylene with n-hexane, n-heptane, n-octane and n-decane at 313.15 K are reported. The results were correlated with four equations for excess Gibbs energy. Comparison of their correlating ability was made. Agreement with literature data was checked. Experimental results were compared with prediction by the UNIFAC method and with the Hildebrand-Scatchard equation.