Kim, Kyoo-hoon This study aims at suggesting ways to establish text typing of writing domain in Korean language education based on ecology. It is originated with critical mind that an existing text type of writing domain could not include an authentic writing which deals with learners’ ecological life, because those text type has a fixed text typing logic. So this study has a premise that the text of writing domain closely relates to learners and their environment and maintains the wholeness, and the text typing of writing domain would be set by these premise. At this point, a study about the relationship and wholeness is “ecology” and the core competence of ecology is “sustainability literacy”. It is a new attempt to establish text typing discourse of Korean language education, that is, the text typing logic based on ecology focusing sustainability literacy. Concretely, writing text features considered with writing competence focused on sustainability literacy follows those three expanded directions. Maximization of the genre dynamics in “text as a mode”, actualization of text strategy by ideal writers in “text of professional writers”, emphasizing text writing of a self-life, especially self-examination in “text of learner writers”. Followed by these facts, “the text typing standard in Korean language education” would be critically considered for concentrating the text typing discourse. As a result, the text typing standard in Korean language education needs a “complex text typing”. But a standard of that complex text typing could be sincerely considered. Ultimately, to have those text typing standard, this study adopts two concepts of “ecological language learning”, “affordance” and “emergence”. And these two concepts connect to two faces of sustainability literacy, the text type of writing domain could be established, “writing text of social relationship” and “writing text of existing awareness”. These two types have subtypes, the former includes “information delivery, persuasion, friendship, emotion expression” as “writing of register”, and the latter includes “past-present, present existence, present-future” as “writing of enjoyment”.