In an effort to examine the hierarchical relations in the development of discourse topics, the narrative-descriptive essays of 55 university freshmen were analyzed in terms of L. Lautamatti's five sentence types. In type 1, the initial element is in the position of the grammatical subject, and is the topical subject. In type 2, the topical and grammatical subject is preceded by an initial sentence element. In type 3, the initial element is also in the position of the grammatical subject, but the topical subject is elsewhere. In type 4, the topical subject occurs in the initial sentence element, while the grammatical subject follows. In the last pattern, type 5, the initial element, the grammatical subject, and the topical subject are all separate. All types are measured as t-units. Results showed that type 1 sentences comprised nearly half of all the t-units in the high and low rated essays. Type 2 t-units, in which the initial element differs from the grammatical and topical subject, comprised roughly one-fifth of the t-units in all the essays, the low rated group using slightly more than the high. Type 3 was produced slightly more than type 2, and type 5 t-units occurred more than twice as often in the high rated and five times more frequently in the low rated essays as type 4. Although the t-units of type 4 occurred relatively infrequently in all of the essays, they appeared nearly three times as often in the high group as in the low. (HOD)