Abstract By following changeful environment and global competition trends, business strategy has an enormous influence toward enterprises. The most significant resource in an enterprise is manpower. Therefore, this research attempts to fit the relationship through environment uncertainty, the enterprise business strategy and human resources flexibility strategy. Besides, the research will discuss the human resources strategy how to make human resources flexibility fit and adjust business strategy practically, then promote to create enterprise competitive superiority, to follow external environment to reach enduring competitive capabilities, and to have double win. This research method adopts depth interviews and discussions with four individual cases. These four companies in this research are high-tech multinational stock companies. Their main products are different¡G crystal, IC¡]Integrated Circuit¡^seal and test, electric capacity, electric photography and scanner, etc. Totally there are 19 companies (including branches and subsidiaries) in investment cases. To build this method construction in this research by literary studies has found out the management connection among these case studies which all get involved with environment uncertainty, business strategy and human resources flexibility strategy. Four key findings are: (1) When the enterprise is aware of the low general environment uncertainty, characteristic business environment uncertainty and industrial environment uncertainty, business strategy should take it in terms of prospector and human resources flexibility strategy should select temporal working day and flexible wages. (2) When the enterprise is aware of the high general environment uncertainty, and low characteristic business environment uncertainty and industrial environment uncertainty, business strategy should take it in terms of prospector and human resources flexibility strategy should select temporal working day and flexible wages. (3) When the enterprise is aware of the low general environment uncertainty and characteristic business environment, and high industrial environment uncertainty, business strategy should take it in terms of defender and human resources flexibility strategy should select functional and numerical flexibility (4) When the enterprise is aware of the low general environment uncertainty and characteristic business environment uncertainty, and middle industrial environment uncertainty, business strategy should take it in terms of analyzer and human resources flexibility strategy should select functional and temporal flexibility. The conclusion is an enterprise must have different business strategies to fit environment uncertainty. If the enterprise can execute the human resources flexibility strategy at all times, they can build up effective management systems, and promote competitive conditions