Liquid-liquid equlilibrium (LLE) data were measured for four binary systems containing N-formylmorpholine and alkanes (i.e. pentane, hexane, heptane, and octane) over the temperature range 298 K to 413 K using circulation type equipment with an equilibrium view cell. The compositions of both light and heavy phases were analyzed by on-line gas chromatography. The mutual solubility increased as the temperature increased for all these systems. The binary liquid-liquid equilibrium data were correlated with the NRTL and UNIQUAC equations using temperature-dependent parameters. Both models correlate the experimental data well. The solubility in N-formylmorpholine increased in the following order at the same temperature: pentane, hexane, heptane, and octane.