An exposure to free choice of inspiring reading materials among Thai students has not been largely promoted in English language class, affecting negative language learning attitudes and development of a reading habit. This present study examined the effects of extensive reading (ER) on Thai university students .To measure their attitudes towards comfort, anxiety, intellectual value, practical value and linguistic value before and after 15- week extensive reading. 68 undergraduate students were asked to complete the 5- point Likert scale questionnaire of 23 items adopted from Yamashita ( 2013 . ) A semi-structure interview was also employed . The results revealed students had positive feelings in which ER increased their comfort and decreased their anxiety at the significance level of 0. 05 .They also had positive beliefs about the intellectual benefits .However, the practical value that ER might bring advantages to students ’study or future career was lower in the posttest .There was no significant difference between the pretest and posttest in their beliefs about English language study benefits .Qualitative data from the semistructured interviews showed that students satisfied with their own choice of reading preference. The findings suggested the use of ER approach in English as a foreign language (EFL) classes to increase students ’ positive attitudes, decrease their negative ones towards reading, and develop good reading habits through their reading engagement.