This paper discusses the tensile properties and acoustic emission behavior of Ni-NiO alloys and Ni-Al₂O₃ alloys prepared by means of the PM method. The mechanical properties of these materials were changed by their manufacturing process conditions. In the case of Ni-NiO alloys, the sintering time of 3.6ks along with repressing and resintering processes may be effective. On the other hand, the best conditions for Ni-Al₂O₃ alloys are the sintering time of 10. 7ks with neither repressing nor resintering. The AE characteristics of Ni-NiO alloys became highly apparent. It appeared that the AE events generated in the region of 5-40% strain were related to the decohesion of the matrix / dispersoid interface. The AE events with high energy and high peak amplitude before fracture of the Ni-NiO specimen were produced by intergranular cracking. The AE activity of Ni-Al₂O₃ alloys was weaker than that of Ni-NiO alloys ; that is, the peak amplitude distribution of AE events generated in Ni-Al₂O₃ alloys became narrow and most AE events had low energy.