To satisfy the demands for production peak, reduce personnel costs for labor, limit the increase of employees in enterprises, and focus on corporate specialty to develop the competitive advantage, enterprises would generally apply human resource flexibility strategy to achieve the objectives. The practice of human resource flexibility strategy would change work-related characteristics; besides, the effect of the system on employees would decide the effort, absenteeism, or turnover. Aiming at supervisors and employees in ecotourism, as the research objects, a total of 500 copies of questionnaire are distributed, and 351 valid copies are retrieved, with the retrieval rate of 70%. The research results reveal positive and significant effects of 1. human resource flexibility strategy on organizational citizenship behavior, 2. organizational citizenship behavior on organizational performance, and 3. human resource flexibility strategy on organizational performance. According to the results, suggestions are eventually proposed, expecting to provide essential assistance for the human resource flexibility strategy in ecotourism and assist in the sustainable development.