The purpose of this study was to investigate Taiwanese adolescent psychosocial development (i.e., autonomy and identity development) based on psychosocial theoretical models developed in western societies. Data were collected from both public senior high and vocational high schools in both urban and rural areas in Taiwan. Adolescent participants, with an average age of 17 years old, included 447 (about 54% were females) from urban areas, and 702 (62% were females) from rural areas. The results of this study revealed that Taiwanese adolescents from both urban and rural areas were similar to adolescent developmental ranges suggested in western theories. There were a few variations revealed in this study, such as scores of internal consistency, average scores of each scale, associations among indicators, and the numbers of youth classified of certain developmental status. In general, the relationships between factors and adolescent psychosocial developmental outcomes did not moderate by regional differences. Identity development of Taiwanese youth from both areas was more likely to be predicted by both situational (e.g., family income and school type) and agential factors (e.g., collectivism, parent attachment, and resiliency) than Taiwanese adolescent cognitive, emotional, and behavioral autonomy. Higher family income level and greater resiliency scores were positively associated with high autonomy and/or achieved identity status. Strong beliefs in collectivism and secure attachments with parents did not significantly correlate with autonomy but did correlate with foreclosure identity status. Across the analysis models in this study, resiliency was the strongest factor which was associated with high autonomous status and identity achievement. Implications and further recommendations for research and practical uses were further discussed.