This study examines two alternative views on the relationship between human resource management (HRM) systems and firm performance : universalistic view and contingency approach. To examine the effects of the HRM systems, and to find the moderating effects of business strategy on organizational performance, and empirical model was developed and tested. HRM systems are, following Pfeffer(1998), conceptualized and measured by seven indicators : job security, selective staffing, self-managed teams and decentralization of decision making as the basic principles of organizational design, high compensation contingent on organizational performance, extensive training, reduced status distinctions and barriers, and extensive sharing of financial and performance information throughout the organization. To test the hypotheses, data were collected through questionnaire instruments from both HRM managers and Planning managers in 83 companies. Sample includes both Korean indigenous firms and foreign subsidiaries from the USA, Japan, and Europe operating in Korea. Several important results have been observed. First, there were some between-home-country variations in HRM systems. Second, HRM systems have positive effects on organization's performance(i.e., learning, internal processes, customer performance and financial performance). Third, business strategy parthly played as a moderating variable for the relationship between HRM systems and organizational performance. Finally, organization's learning has a positive relationship with customer satisfaction, hence mediating the two variables. The results found in this research imply that HRM systems can be a critical source of the competitiveness of an organization.