This presentation reports about improving reading comprehension through extensive reading activity. The action research on an extensive reading activity after a whole-class reading tells us the activities are in great need among the secondary school English learners. The whole–class extensive reading activity was conducted in 11 provinces in 8 districts with 62 teachers for 1504 secondary school students in Mongolia. The result of the action research showed; I) using extensive reading activity improved the learning process of English, II) the students expressed good responses about the extensive reading activity which was whole class reading, III) organizing a whole class reading activity improved class unity and overall responsibilities on behalf of class name or school names. In short, before the whole class extensive reading activity, the students focused on their own results and individual academic progress but after a month of the whole class extensive reading activity, the students expressed they had a better class atmosphere and all tried for one goal. Then they highlighted that they are ready to conduct the next extensive reading activity for improving their English in all four skills through reading.