Hambrick and Mason¡]1984¡^, with their ¡§upper echelon¡¨ perspective, proposed that top managers had great influences on organizational performances. Then, more and more scholars paid attention to the issues of the top management teams¡]TMT¡^. Although the impact of top management teams has been widely studied, research that tests the applicability of TMT variables on MNC is zero. The top management teams of the MNC included expatriates and local managers¡]Tung, 1982; Zeira and Shenkar, 1986¡^, would show higher richness and variety. Therefore, this study will use two independent variables: ¡uthe strategic roles of MNC subsidiaries¡vand ¡uthe nationalities of the MNC¡vto study the influences of these two independent variables on the traits, heterogeneity and interaction of the top management teams of the subsidiaries in Taiwan. The traits of the top management teams included the percentages of the local managers, average age, educational level and organizational tenure of the top management teams. The heterogeneity of the top management teams included the variation of the age, educational level and organizational tenure of the top management teams. The interaction of the top management teams included the extent to the social integration, communication frequency, and informal communication of the top management teams. Using ANOVA analysis on samples of 46 manufacturing MNC subsidiaries in Taiwan, the study finds that the strategic roles of the MNC subsidiaries have significant influences on the educational level, social integration and communication frequency of top management teams. In addition, the nationalities of the MNC have significantinfluences on the age, educational level and organizational tenure.