In this study, the solubilities of ethylene in 2,2,4-trimethylpentane solvent at various temperatures between (323.15 and 423.15) K and pressures between (0.5 and 2.5) MPa were measured by the pressure decay method with vapor composition being analyzed on-line with a gas chromatography. The experimental results show that the solubility of ethylene in 2,2,4-trimethylpentane increases with increasing pressure and decreases with increasing temperature. The experimental data were also expressed in terms of vapor-liquid equilibrium and correlated by the bubble-pressure calculation with the Peng-Robinson equation of state incorporated with the van der Waals one-fluid (vdW-1) and the Zhong-Masuoka (Z-M) mixing rules with the consideration of binary interaction parameters. The results showed the vdW-1 mixing rule is slightly better than the Z-M mixing rule for pressure correlation, but the Z-M mixing rule is slightly better for vapor composition correlation. A semiempirical four-parameter solubility equation in terms of temperature and pressure for the present binary system was proposed. This proposed model is simpler and capable of estimating the solubility with AARD smaller than 5.0 % for the present system.