This study analyzed the effects of learner characteristics related to their English learning backgrounds on Listening
Diagnostic Assessment results. To accomplish this aim, 283 Korean online university students were surveyed about the
characteristics of English learners, and then a Listening Diagnostic Assessment of 10 subskills was conducted. Based on the
results of the questionnaire and Listening Diagnostic Assessment, the effects of English learner characteristics on both the
total score and the subscores of Listening Diagnostic Assessment subskills were investigated. The results of the study are as
follows: First, the period of visits to English speaking countries, the time exposed to English audio/visual materials, English
reading time, and conversation time with native English speakers were found to be significant factors that affected the total
score of the Listening Diagnostic Assessment. Second, conversation time with native English speakers was found to be significant
in the subscores of both the voice recognition and phrase/sentence identification subskills. Third, the period of visits to
English speaking countries was found to be significantly related to the subscores of most subskills, and both the time exposed
to English audio/visual materials and English reading time were found to be significant characteristics of the subscores of
more than two subskills. Based on these results, practical suggestions related to listening courses were given to the instructors,
the English contents developers, and the English curriculum developers of Online Universities.