The aim of this study is to analyze the influence of microstructure on thermal shock resistance of liquid phase sintered SiC, as this is a very required property in various technological applications. The microstructure can influence the thermal shock resistance because large grains tend to generate toughening mechanisms, reducing damage to the material. For this analysis, samples with 90 % SiC 10 % + (Y2O3:Al2O3) in the proportions 1: 3 and 1: 4 mole, were compacted and sintered at 1750 ?? C , 1850 ?? C and 1950 ?? C. The thermal shock was performed by heating the sample in a tubular furnace and quenched in water. Damages caused by thermal shock were evaluated by monitoring the elastic modulus of samples. Micrographs were done by electron microscope and grain size distribution at Quantikov software. The samples sintered at 1950 ??C have greater grain size and, consequently, greater thermal shock resistance.