Mo₂FeB₂ based cermets with different Mn contents were prepared by in-situ reaction liquid sintering. The effects of Mn content on the microstructure, mechanical and tribological properties were investigated. The observation of microstructure showed that the hard phase particles were distributed uniformly in Fe based binder. The mechanical properties of the cermets increased with the increasing of Mn content, due to grain refinement and solid solution strengthening. The inter-granular fracture was the main fracture mechanism of the cermets. The tribological behavior of the cermets was closely related to their mechanical properties. The cermet with 5 wt.% Mn content showed the best wear-resistance owing to its superior comprehensive mechanical properties. The wear mechanisms of Mo₂FeB₂ based cermets under dry sliding were primarily caused by abrasive wear, accompanying adhesive wear and oxidation wear.