Abstract The phase equilibria in the Co–V–Mn ternary system, the magnetic properties and the phase stability of the new ternary intermetallic compound Co2VMn were investigated by means of electron probe microanalyzer, X-ray diffraction, differential scanning calorimetry and the vibrating sample magnetometer. Four isothermal sections of the Co–V–Mn ternary system at 1073K, 1273K, 1373K and 1473K were experimentally established, and a new ternary intermetallic compound named Co2VMn was found in the Co–V–Mn system. The Curie temperature of the Co2VMn phase was found to be about 670K. In addition, the saturation magnetization at room temperature for alloy with B2 structure was measured to be about 145.1 emu/g, while the coercivity was about 2.8Oe. The newly determined phase equilibria in this system will provide important information for the development of the Co-based functional materials and for the thermodynamic assessment of the Co–V–Mn ternary system.