Abstract: The diluent s ( Al₂O₃ , Cr₂O₃ ) and reactive additive ( MoO₃ ) were added to Al-Cr₂O₃ system.Al (Cr) ₂O₃-Cr (Mo) ceramic mat rix composites with eutectic mixture of fine rod metal phase were successfully fabri2cated by means of the thermal explosive combustion synthesis method. The effect s of the reactive system composi2tion and preparation process on the microst ructure of the composites were investigated. The product s with about 90percent relative density were obtained at a pressure of 1. 26 MPa on the synthesized material melt . The ceramicphase has three morphologies , block grains with round edges , fine rectangular slab grains with different orientationsand coarse rectangular slab grains. Metal particles dist ribute int ragranularly or intergranularly in the ceramic crystalgrains , or eutectic st ructure forms. The eutectic mixture has a quasi2regular st ructure. The fine rod metal phasedisperses in the continued ceramic mat rix. The eutectic mixture is regionally dist ributed throughout the specimen.The microst ructures of the fabricated composites are principally characterized by in si tu rectangular slab ceramicgrains and the rod eutectic mixture.