Using　the　BP　Artificial　Neutral　Network　(ANN)　with　the　Levenberg-Marquardt　algorithm,　High-Pressure-Vapor-Liquid　Equilibrium　data　of　methane,　ethane　and　ethylene　system　were　calculated.　Temperature,　x(1)　and　x(2)　were　used　as　input,　and　Pressure　and　y　as　output.　The　comparison　of　the　results　showed　that　ANN　can　be　successfully　used　to　predicted　vapor-liquid　equilibrium　at　high　pressures,　and　could　be　an　effective　method　in　VLE　data　processing　at　high　pressure.