The present paper reports on the fabrication and the mechanical properties of SIC (Hi-Nicalon) fibres reinforced Si3N4 matrix composites. The composite was fabricated by liquid infiltration of an aqueous Si3N4 slurry followed by hot-pressing. The effect of fibre coating layers was investigated with a 400 nm thick pyrolytic carbon. The fibre coating was found to have a significant effect on the frictional stress of the fibre-matrix interface and consequently on the fracture behaviour of the composite.