This study aims to investigate the differences in Meister high school students’ learning motivation and demotivation factors according to their grade, English proficiency, and English improvement. The participants are 86 students who attended a three-week intensive TOEIC program. A questionnaire survey and mock TOEIC scores were used for data collection. The findings reveal that 1) in terms of learning motivation second grade students’ instructional motivation level was significantly higher than that of the first grade, and among the demotivation factors, the second grade participants’ learner factor, in-class environmental factor and out-of-class environmental factor were found to have a higher mean difference, 2) there was no significant difference in the learning motivation level between groups classified by English proficiency but the lower English proficiency group showed significantly higher levels of demotivation in the learner factor than that of the upper group, 3) there was no significant difference in the learning motivation and demotivation levels between groups in the TOEIC score improvement, and 4) while employment was the main motivation for TOEIC study, the difficulty of studying TOEIC vocabulary, grammar, and listening was the primary source of demotivation. Also, some suggestions for remotivation were provided.