The purposes of this study were: (a) to compare the differences of physical fitness, physical self, and global self between children of Taiwanese aboriginals and Taiwanese Chinese; (b) based on Fox and Corbin (1989) model, to compare the predictability of children's physical fitness and physical self on global self between Taiwanese aboriginals and Taiwanese Chinese. Participants were 164 Taiwanese aboriginal children (mean age=11.90; SD=0.70) and 160 Taiwanese Chinese children (mean age=11.74; SD=0.68). After obtaining permission from participants' or guardians, the authors tested participants with the Taiwanese Standard Physical Fitness Test (TSPFT), Children's Physical Fitness Scale (Chuan, 1996), and Children's Self Description Scale (Zhao, 2002). A t-test statistical analysis found Taiwanese aboriginal children were higher on the sit and reach test, one-minute sit-up test, and standing broad-jump of TSPFT compared to the Taiwanese Chinese children. However, two separate path analyses found that only the Taiwanese Chinese children's fitness were both direct and indirect predictions of global self through physical self as Fox and Corbin (1989) suggested. In terms of Taiwanese aboriginal children, fitness performance failed to predict global self through physical self as Fox and Corbin (1989) suggested. This study concluded that due to cultural differences, a common performance of TSPFT was unable to represent Taiwanese aboriginal children's true physical concept and suggests that future studies applying diverse physical abilities tests such as distant running and sports skills to examine Fox and Corbin's (1989) model.