The study investigated a first-time ER instructor’s reflections in implementation of extensive reading, how she found the difficulties after observing students’ reflections, examined the factors that might affect students’ reading motivation, and perceptions of the ER approach. The participants consisted of a first-time ER instructor, two EFL classes, and a well-experienced EFL teacher. The current study was an action research that used qualitative data analysis, including the instructor’s weekly diary, pre- and post-reading attitudes and motivation questionnaires, students’ interview, and the teacher’s interview. The participants were divided into two groups, one of traditional extensive reading (ERG), and the other of extensive reading with post-reading activity (PRG). Questionnaires and interviews were collected after a total of 13 weeks of ER. The results of qualitative research showed that (1) I found the difficulties of applying extensive reading relating to her lack of teaching experiences, and participating students confronted reading influences from both intrinsic and extrinsic motivation, (2) PRG students gained highly motivation than ERG students, some students disagreed with the ER effects; likewise, some ERG students still held positive experiences in English reading, (3) the EFL teacher discussed learners’ background, age, time, instructor’s experiences and challenges that were connecting to the effects of the study. In addition, the study revealed that not only teacher-students relationship had great influence on reading willingness, but also individual reading attitudes was a factor affecting their motivation. The findings recommended for the teachers who have not experienced the extensive reading approach that they should design the extensive reading carefully, establish the positive relationship with students, provide opportunity to discuss reading and improve their interests, and achieve the objectives of pleasure reading.