Abstract: By ways of one-year empirical contrast teaching, questionnaires, dictionary use tests, observation and interviews, the paper investigates the effectiveness of combining dictionary use instruction with college English teaching for middle and low achievers. The findings confirm the effectiveness of the teaching for middle and low achievers of non-English majors. It is suggested that English teachers should systematically and consciously combine the dictionary use instruction with classroom teaching, and cultivate students' abilities of using dictionaries to solve problems alone.