In order to assess the relationship between knowledge of language structure and reading comprehension, the English Language Structure Test was constructed. In this test, students had to reconstruct scrambled sentences of controlled complexity. The English Language Structure Test and the Stanford Reading Test were administered to 202 junior high school students. Analysis of the data indicated that there was a significant correlation between the two measures, that the various sentence patterns used in the test presented different levels of difficulty, that eighth-grade students had greater knowledge of grammatical structure than had seventh-grade students, and that females performed more successfully on the English Language Structure Test than did males. (Author/AA)