A concept is a building block of a theory. The purpose of a concept analysis is to clarify the critical attributes of a concept and identify its real meaning, particularly if the concept is not understood in a clear and accurate manner. This study was conducted to analyze the concept of support, which has been adopted from another discipline and unclearly used in nursing science. For concept analysis of this study, Walker and Avant's method was used. Support is defined as a domain with emotional, informational, material and evaluative aspects. Critical attributes of the concept of support included (1) an experience of support between a support provider and a client, (2) communication, (3) a relationship of mutual interchange of emotional, informational, material, evaluative support, and (4) intention. Cases related to the concept of support included model cases and appendix cases (against, boundary, and related). Antecedents of support were anxiety, depression, and loss of self-esteem, and consequences of support were comfort, increase of self-esteem, and trust. Based on these results, a nursing intervention that can provide a better quality of life for the prevention of diseases, health management, and health promotion may be developed in the future.