Dense SiC with addition of CeO 2 was obtained by liquid phase sintering using different additives (Y 2O 3, Al 2O 3) and (Y 2O 3, AlN). The total amounts of additives (Al 2O 3 + Y 2O 3) and (AlN + Y 2O 3) were fixed at 10 mass.% and 10 vol.%, respectively. Two different molar ratios of Al 2O 3:Y 2O 3 additives, 1:1 and 5:3, were selected for investigation. Ratios of AlN:Y 2O 3 were selected as 3:2 and 4:1. Influences of both different ratios of Al 2O 3:Y 2O 3 and AlN:Y 2O 3 and amounts of CeO 2 on sintering behaviour were investigated. The phase reaction products were identified by X-ray diffraction and microstructures were investigated using scanning electron microscopy with energy dispersive X-ray spectroscopy techniques. In the samples using Al 2O 3 + Y 2O 3 as sintering additives, the CeO 2 was dissolved in Y 4Al 2O 9 phase during sintering. The oxidation state of Ce 4+ changed to Ce 3+ and Ce 3+ occupies Y 3+ positions, causing increases in lattice parameters for Y 4Al 2O 9 with CeO 2 content. In samples with AlN + Y 2O 3 as sintering additives, Y 10Al 2Si 3O 18 and Y 2Si 3N 4O 3 were formed in the CeO 2-free and CeO 2 containing compositions. During sintering, the CeO 2 dissolves in oxynitrides via a similar mechanism as in the Y 4Al 2O 9 phase.