Ferromagnetic MnAlC (¸-phase) can be synthesized by a single-route conventional reactive sintering method. The maximum magnetization and coercivity were 75.8 Am /kg and 57 mT, respectively. The ¸-phase fraction was evaluated to be 81 mass% for Mn Al C annealed at 1273 K. The ¸-phase of Mn Al C can be synthesized at an annealing temperature from 873 to 1273 K, whereas that of Mn Al cannot be synthesized. It was indicated that the phase stability of the hcp-phase (¾-phase) was improved by adding carbon, resulting in an ¾¸ transformation. 2 55 45 2 55 45 2 55 45