Adolescent gambling has raised concern among the public as it entails an array of significant adverse consequences. With the dramatic expansion of gambling opportunity and the wide acceptance of gambling as a harmless and entertaining activity, the number of adolescents involved with gambling activities has increased. As such, there is growing interest among researchers in studying factors that are associated with adolescents’ gambling behavior. Nevertheless, this important research area has been surprisingly under-studied in Chinese populations, particularly, with adolescent samples. Adolescent gambling has raised concern among the public as it entails an array of significant adverse consequences. With the dramatic expansion of gambling opportunity and the wide acceptance of gambling as a harmless and entertaining activity, the number of adolescents involved with gambling activities has increased. As such, there is growing interest among researchers in studying factors that are associated with adolescents‟ gambling behavior. Nevertheless, this important research area has been surprisingly under-studied in Chinese populations, particularly, with adolescent samples. Three sequential studies with mixed methods were designed to achieve the above objectives. Study I aimed to explore what Chinese adolescents think would happen if they were to gamble. Using focus group discussion, 14 adolescents were interviewed. The results identified multiple themes including material gain, social benefit, enjoyment/arousal, tension/boredom, self-enhancement, relational cost, out of control, monetary loss and behavioral problems. In addition, the item pool of the Chinese Adolescents Gambling Expectancy Scale (CAGES) was also generated from Study I. In Study II three measures were constructed and validated using 258 Chinese adolescents: the Chinese Adolescent Gambling Expectancy Scale (CAGES), the Gambling Subjective Norms Scale (GSNS) and the Chinese version of the Gamblers’ Belief Questionnaire (GBQ-C). The findings of this study indicated sound psychometric properties for all these measures in general, thus justifying their use in Study III. Study III examined the relationships among gambling outcome expectancy, subjective norms about gambling and perceived behavioral control, as proposed by the theory of planned behavior, and gambling behavior among 1218 Chinese adolescents. The findings of this study showed that gambling outcome expectancy had incremental validity to predict both gambling behavior and intention to gamble among Chinese adolescents. Two other well-known constructs, i.e. subjective norms about gambling and perceived behavioral control were also important predictors of gambling behavior as well as intention to gamble among Chinese adolescents. Compared to positive outcome expectancy, subjective norms about gambling and illusion of control, it is noteworthy that negative outcome expectancy and belief in luck/perseverance played a more pivotal role in problem gambling among Chinese adolescents. The theoretical and research contributions and practical implications of this study are discussed along with the limitations and recommendations for future studies. / published_or_final_version / Social Work and Social Administration / Doctoral / Doctor of Philosophy