To do conservation for ceramics, sometimes it needs to clean the ceramics chemically to remove stains on the ceramics, which should be performed with caution. This study will provide quantitative data about the extraction characteristics of major elements from ceramics through the soaking test to evaluate the stability of ceramic cleaning agents. As soft textured pottery(fired at 700℃) had high absorption, it showed higher extraction characteristics in short soaking time. Especially the strong acid among chemical cleaning agents caused the expoliation and the color change on the surface of soft textured pottery. But these color change had no effect on the physical characteristics of soft textured pottery. The hard textured pottery(fired at 1,000℃) is relatively stable in the cleaning agent because it is ascertained the extraction of that was not enough and also it had little chromatic and physical change by strong acid. Porcelains(Celadon, Whiteware and Puncheong ware) was safer than the soft textured pottery due to their low extraction. But it should take precautions to clean the porcelains with lots of cracklewares such like Puncheong ware chemically in connection with the extraction characteristics and their cracklewares.