Listening comprehension is a difficult skill for foreign language learners to develop. In designing suitable listening comprehension tasks, different forms of activities can be provided to reduce the demands of the task for the test takers (Chang & Read, 2006). Pre-listening activities are some preliminary activities acquainting students with the topic of listening task and activating their background knowledge on the content. This study investigated the effects of two pre-listening activities, bottom up as reviewing the unfamiliar vocabularies before the test and top down activities as participating in a discussion about the topic of listening tasks, on learners' overall listening ability and there is an investigation on the difference between the two types of prelistening activities. To achieve these aims, a total number of 47 Iranian elementary learners (in ninth grade high school) were randomly assigned to two experimental groups (each 17 participants), and one control group of 16 participants, based on their scores in KET test. Each groups participated in the pretest under similar conditions, then, group 1 deceived a glossary of unknown vocabularies related to the listening tasks and the group of participated in a discussion related to the topic of the listening tasks, the third group, as the control group, received no prelistening treatment. Then, the posttest was conducted and the means of the three groups on the posttest were calculated. The results of a series of one way ANOVAs indicated that both types of activities bottom up and top down, were eflective. There was not any significant difference among the effect of different kinds of activities, bottom up vs. top down activities, regarding elementary learners' ability of listening. The findings of the study can have some implications for EFL students, teachers and text book designers.
