This paper focuses on an aspect of transmitting knowledge concerning onggi (Korean earthenware) production, in regard with onggijeom (onggi workshop) of Kim Il-man, a skill-holder of Important Intangible Cultural Heritage. Since the application of transmitting knowledge is materialized while preparing soils, shaping onggi, glazing and drying onggi, making kiln and then firing them, I personally contemplate the transmitting knowledge of production process thoroughly. In addition, I try to apprehend the knowledge system in connectivity of entire onggi production as well as individual transmitting knowledge of each process of production.The transmitting knowledge concerning onggi soil is comprised of distinguishing suitable soils for onggi making, and of preparing soils to shape onggi. The transmitting knowledge regarding onggi glazing and drying is comprised of the knowledge of glaze materials and the method of onggi drying. The transmitting knowledge of making kiln is to pile up onggi horizontally. Besides, another transmitting knowledge of making kiln is to pile up onggi separately for not latching onto another onggi, and to pile smaller onggi into large onggi in order to increase productivity. The transmitting knowledge of firing kiln can be the space of kiln and the properties of fire; state change of onggi; the nature of fuel; the influence of external environment and so forth.The transmitting knowledge of onggi production is technically systemized, and intrinsic transmitting knowledge exists in every steps of onggi making. These transmitting knowledge can be seen as the knowledge system which is accumulated by sensible learning of various experiences for a long period. The transmitting knowledge, like as scientific knowledge, is a rational knowledge for whom transmit and practice, thus it would be the standard of decision to carry out onggi production skills. In addition, body senses are considered for knowledge system of onggijang (onggi maker). Since sight and hearing are used while making onggi, there are several transmitting knowledge concerning these senses.It can be seen that the transmitting knowledge of onggi production is quite technically systemized. Onggijang (Korean earthenware maker) begins to produce onggi considering the final process of onggi making. Suitable onggi soil is selected for shaping and deformation, and shaping skills of onggi making are designed by piling up and firing onggi. Thus, transmitting knowledges inherent in each production process co-exist with mutual connectivity, not as individually.