This paper analyzed the thematic structure of Japanese intermediate EFL college student writing to identify the textual features of higher rated and lower rated essays. As an analytical tool, the Theme-Rheme structure of Halliday's functional grammar was used. The thematic progression patterns, which contribute to making coherence and an overall impression of a text, were examined by focusing on what ideas were chosen for the sentence element that came first in each clause. The type of essays examined was expository writing discussing a social problem. The results showed that both higher and lower rated groups used similar types of thematic patterns overall, but differences in the use of constant and linear thematic patterns were observed between the two groups. Moreover, a similar difference in the use of thematic patterns was observed within the higher rated group. Such differences in the use of thematic patterns were found to be related to the level of writing ability of the writer and the type of topic discussed.