Kim Kwang Soon. 2015. The aspect of extension and use of kinship terms of address-in the center of {hyeong}, {nuna}, {oppa}, {unni}. Korean Semantics, 48. This study on the characteristics of the aspect that {hyeong}, {oppa}, {nuna}, and {unni} included in kinship terms in Korea are extended to and used as the terms to address people in a non-kinship group. Kinship terms are lexeme selected and used based on [blood relations]. However they are also used in subjects to [-blood relations] in modern language life. This means that Korean language users don’t recognize these lexeme in the center of [blood relations] in their cognitive structure and other particular characteristic plays an important role in the extension and use of these lexeme. This particular characteristic is the attribute that makes it possible to use {hyeong}, {oppa}, {nuna}, and {unni} used in kinship group naturally in non-kinship group and the primary purpose of this thesis is to identify this particular characteristic. Based on this, the secondary purpose of this is to identify the aspect of each lexeme being extended and used individually and to constitute the semantic network that makes it possible to arrange the attribute that is involved and identify the aspect of the extension and use of {hyeong}, {oppa}, {nuna}, and {unni}. It is to identify what the most important characteristics that Korean language users recognize are and what kind of characteristics make it possible to use these naturally, when kinship terms are used in a non-kinship group through the confirmation of the use of {hyeong}, {oppa}, {nuna}, and {unni} that are arranged like this.