Abstract: This study probes into the influences of implementation strategies of Total Quality Management (TQM) and organizational culture on execution degree of TQM activities and the effect of execution degree of TQM activities on operational performance. The subjects of this research were Taiwan’s high-tech firms in the Hsinchu Science-Based Industrial Park and Southern Taiwan Science-Based Industrial Park. Quality management supervisors in the companies were the target respondents. The design of the questionnaire items was based on literature review. The research findings reveal that implementation strategies of TQM (cost leadership strategy and differentiation strategy) have significant influence on the execution degree of TQM activities; Organizational culture significantly influences execution degree of TQM activities; TQM activities execution degree significantly influences operational performance (quality performance, financial performance and inventory management performance). When reinforcing the operational performance, the firms should first enhance the execution of TQM activities. In order to significantly enhance execution degree of TQM activities, the firms can improve the implementation of cost leadership and differentiation strategy and combine the characteristics of four cultures (group culture, developmental culture, hierarchical culture and rational culture).