One should keep learning at his / her working places in order to obtain new knowledge and skills as well as adjust them to the society. The main purpose of this study is mainly aimed at the 2-year college in-service students in the Department of Applied Foreign Languages, NTCB, to explore the motivations of adults studying in the extension junior 2-year college as their in-service education and investigate the effects of the different motivations and their learning results. Content analysis and questionnaire survey are used. We discovered that among the motivations, vocational progress is the influential one; and the next are self development and cognitive interests. The most important items are “promoting the educational background”, “increasing the working abilities” and “learning more knowledge and skills for work”. Besides, the curriculum of the department is also the emphasis. Moreover, based on the orientation of each motivation, adult learners’ toward studying in 2-year college as in-service education will be subject to genders, ages, grades, marital status, education, majors, occupations, positions, faiths, and years of working. Examining the relationship among learning motivation and the qualifications of license examinations, the achievements of competitions, and students’ academic grades, we discovered that if the 2-year college in-service students’ learning results are better than those of others if their initiative motivations are higher. Besides, more than 92% students are stressed at works and examinations, and more than 60% students pay schooling by themselves. Most of them are freshmen in the business; they may feel confused and impotent in this difficult situation. Many establishments support their employees to keep learning, but it may cause some hidden social problems. How the schools and the establishments help the young in-service students study in a positive environment is worth investigating.