The observation of ferromagnetism in CeCo3B2 with a high Curie temperature TC = 140 K and a magnetic moment 8 × 10−3 µB / has been presented and explained by 4f itinerant magnetism with strong 4f-4f direct exchange interaction. The observed small magnetic moment can be understood by a cancellation of 4f orbital and spin contributions and of 5d polarized contribution to magnetic moment. | Ferromagnetism in CeCo3B2