This study is the structure and content of `composition` subject of highschool in 2009 National Curriculum. Now a highschool elective subject is one-to-one correspondence the territory of National Curriculum of Korean Language(k1-k9). But I think highschool elective subjects is based on the korean language ability to learn through k1-k9. So, the `composition` subject is intensified both National Curriculum of Korean Language and its `writing`. And the `composition` subject focus on the creative idea, problem solving, progress of idea, synthesize of idea and so forth, while `writing` of National Curriculum of Korean Language(k1-k9) focus on the basic skills on writing. The `composition` subject as an elective course has to have competitiveness to another elective course in Korean subject and the elective course of another subject. It is in complementary relations with another elective course in Korean subject. Especially, it is much the same with `speaking`. So, two would be better to be united to be one course.