It is a widely accepted view that teaching is a complex process in which teachers attempt to transfer specific knowledge or targeted skills to students under certain circumstances. The process achieves attributes of complexity, mainly due to circumstantial or personal factors, and in some cases due to the interaction of both. Conditions for teaching become unfavorable when the inclusion of students in a program is inappropriate, teaching materials are not in line with students' needs, interests and level of competence, teaching aids and learning are insufficient, the teaching style is not suitable and so on. Most of these factors cause students to lose interest in learning. This loss of interest is one of the very important reasons behind the failure of effective teaching. Investigating the causes of demotivation is a relatively new area of ​​research in L2 learning. This essay uses a study conducted to identify common causes of demotivation for L2 learning at the Japanese high school level. Falout Joseph, Elwood James, and Hood Michael conducted a study in 2009 interviewing 656 L2 Japanese students at several high schools. The study found the following five demotivating factors:1. Contents and teaching materials,2. Teacher skills and teaching styles,3. Inadequate school facilities,4. Lack of intrinsic motivation5. Test scores. (ibid.) The study indicated that the majority of L2 learners consider learning content and materials and test scores as strong demotivating factors. However, teachers' competence and teaching styles were found to be less demotivating factors than other factors (ibid.). Although the study was conducted on Japanese students, the results may be more...... middle of paper ......able. So, to conclude, it can be said that motivation in all its facets is an important agent that influences human behavior positively on outcome-based tasks. And its lack is one of the major obstacles that affect the results obtained. Psycholinguists have been studying it for a long time, but a notable boom in this field has been observed since the mid-20th century, when Dr. Robert Gardner began to conduct more in-depth research in the field. It has been called a complex phenomenon that influences human behavior in intricate ways. The importance of motivation led the program designers to design student-centered learning materials, full of interesting activities planned after conducting analyzes based on interests and needs. Education policy makers have begun to propose methods that meet students' beliefs and interests more than ever before.