Carbon-encapsulated Fe-Co alloy nanoparticles (Fe-Co(C)) have been fabricated with different Co/Fe ratios by an efficient solid-state route using melamine as carbon source. The structure and morphology of Fe-Co(C) nanoparticles were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The XRD characterization results reveal that all products are alloys with no carbide impurity. The TEM and HRTEM observations show that the alloy nanoparticles are encapsulated in carbon shells. Additionally, the reactions involved in the syntheses are postulated. The variation of magnetic properties of Fe-Co(C) with Co/Fe has been discussed according to the room temperature VSM measurement results.