Abstract: Fe-based coatings were deposited by plasma spraying. The rolling contact experiment was conducted on a ball-on-disc tester. The fractures of the coatings were monitored by acoustic emission (AE). The propagation of cracks in the coating was investigated. Results showed that the deposited coating had a dense microstructure and was mainly composed of ferrite. There were many amorphous/nanocrytalline phases in the coating. The critical status to failure can be characterized by acoustic emission (AE) signals. The ductile transcrystalline fracture was the main propagating mode of cracks in the coatings in the rolling contact.