Onggi described as a breathing pottery has significantly influenced the traditional food culture in Korea.It is known that Onggi is optimal storage for the fermented food such as soy sauce, salted seafood, and Kimchi since air or liquid can penetrate through the body.These foods are gaining flavor by the breeding of the aerobic bacterium at the beginning of fermentation process.In this study Onggi materials from five regions including Gangjin, Yeoju, Ulsan,Yesan, and Jeju in Korea were collected and analyzed for chemical and physical properties before and after sintering.Among them Gangjin raw material has the biggest mean particle size of 92.29 μm as well as the widest particle size distribution.The differences in the levels of SiO2 and Fe2O3 are shown among Onggi raw materials.However,crystalline phases formed after sintering are identical except Jeju.At all the sintering temperatures Gangjin Onggi has the highest porosity, leading to the complete air permeation through the body within 90 minutes.All the results indicate that air permeation is strongly related to the pore structures in Onggi body.This is assumed to affect the fermentation behavior.