Two different groups of Si₃N₄ based composites were prepared within the present study. The first group consisting of materials containing SiC nanoinclusions in Si₃N₄ matrix, the second one with the same SiC/Si₃N₄ composition containing different size of graphite particles. Wet volume abrasive wear of these two groups of materials was studied. Wear mechanisms of the first group is mainly transgranular fracture. The dominant wear mechanism of second group is changed with the increased load from transgranular to the intergranular. Significant role plays the weak graphite/matrix interface. The pull-out of SiC/Si₃N₄ grain agglomerates from this area deteriorates a possible lubrication effect of graphite during the test. No significant benefit of the application of graphite particles in respect to the wear behavior was observed in the present study.