This thesis is focused on the question of motivation among adult students and the ways in which it can be theorised and investigated. The idea was prompted by three areas of concern. First, the large body of literature on achievement goal theory is developed in the West involving school children and young adults. Second, research in cross-cultural motivation issues has also been focused on young learners. Third, research on adult learners has been fragmented and sparse. Little is understood about the motivation of adult learners in a Confucian Heritage Culture, such as Hong Kong. The purpose of this study is to explore the transferability of achievement goal theory to Chinese adult learners. Based upon the social-cognitive framework, this study enquires if personal, behavioural and environmental factors of Chinese adults' achievement motivation can be satisfactorily explained by Western theory that is developed with young learners in mind. A heuristic approach is adopted to explore personal perceptions and understandings of aspects relating to adult learners' motivation. In the first part of this study, the construct systems of 27 part-time Chinese adult students were explored using Repertory Grid interviews. In the second part of the study, the interview data were validated by data triangulation using two focus groups. The data showed that Chinese adults were primarily motivated by extrinsic goals in an avoidance orientation, while holding a firm belief in effort and hard work. Analysis of the data showed considerable differences between important elements suggested by the Western theory and important motivation factors revealed by the sample. In the final analysis, cultural as well as developmental factors were found to attribute to the gap between Western theory and Chinese adult learners. The thesis concludes by discussing the implications of the findings and the strengths and limitations of the research.