The thermal shock behavior of ceramics with the cooling medium temperatures in the range 5 degrees C to 100 degrees C has been studied in detail by measuring the retained flexural strength after water quenching. The test materials is ZrO2(3Y). Results show that the thermal shock resistance of ceramics is very sensitive to the cooling medium temperature, even which is very low. When characterizing the thermal shock resistance of ceramics the effect of cooling medium temperature should be taken into account. A higher water-bath temperature may not correspond to a greater thermal shock resistance of ceramic materials owing to the effect or thermal shock initial temperature on the material properties. When the temperature difference in thermal shock is close to the critical temperature difference or rupture, a little change of which can cause a great change in the retained strength of materials. As the retained strength of materials is too sensitive to the temperature difference close to the critical temperature difference of rupture, it is unsuitable to use the critical temperature difference of rupture to characterize the thermal shock resistance of ceramic materials. This study shows some innegligible problems in the evaluation system for the thermal shock resistance of ceramic materials. (C) 2014 Elsevier B.V. All rights reserved.