This study aims to set the components of writing assignment when authors write essays. In this study, the study on the types of writing, the research on the effect of practical writing on the students and the comparative study on writing were reviewed multilaterally. As a result, the existing assignments have been found that it included a variety of subjects, objects, readers, etc. as components by implication and manifestation. Above components of writing assignment had difficulties leading students' different and deep thoughts so this study guides writing assignment in the types of the authors' understanding and the situation of assignment. The authors' understanding means the knowledge of the subjects as well as strategic understanding of writing's object, process and readers, which were already inherent in authors but revealed in the process of writing. The situation of assignment includes criteria and time, etc. which caused authors to limit from outside. Students could been encouraged as authors by having ample opportunity for writing about different objects, subjects and readers. In order to provide these experiences, the components of writing assignment like subject, object, writing process, readers, criteria and time should be offered in many types. These components, however, acts differently on the students' grades so the study on setting rank of writing assignment based on the cognitive complexity, and the empirical study on the design of practical writing assignment and students' performance are left as follow-up study subjects.