This study explores the factors that influence the design and execution of MNCs' HRM systems in their overseas subsidiaries. Through in-depth interviews with multiple managers from four Taiwanese MNCs, this study compares the HRM similarities between MNC headquarters and their overseas subsidiaries in China. We found MNCs' control systems, degree of internationalization and their strategic international human resource management (SIHRM) orientation significantly affect the design of subsidiary firms' HRM systems. When the MNC has high degree of internationalization, when it utilizes output control system, and when it adopts ”adaptive” SIHRM orientation, HRM systems in subsidiaries adjust to local demands and exhibit large differences compared to that of the HQs'. If the MNC has low degree of internationalization, when it utilizes input, behavior control system, and when it adopts integrative or exportive SIHRM orientation, HRM systems in subsidiary firms exhibit high similarities to that of the HQs'.