Abstract: With the continued advancement of economic globalization, the acceleration of technological innovation and the increasingly fierce market competition, enterprise’s strategic flexibility need to be improved to adapt to the dynamic environment. Chief Executive Officer (CEO) plays an important role in the process of enterprises' perception of environmental change and improvement of strategic flexibility, because CEO controls key resource of enterprise and influence the formulation and implementation of enterprise strategy. A CEO with transformational leadership can inspire the TMT (Top Management Team) members' proactivity and spirit of dedication, create a good learning environment, stimulate creativity of team members, and affect the improvement of enterprise performance. However, the existing studies on transformational leadership have focused on how transformational leadership behavior affect individual behavior. Although some scholars have studied the influence of transformational leadership behavior on group psychological characteristics from the enterprise level, such as the enterprise culture, entrepreneurship, competition strategy, and organizational learning and innovation research variables, the research is still very limited and also neglect the impact on the develop of organization ability. The research of strategic flexibility mainly studies the formation of strategic flexibility from the view of enterprise resources, products, network structure and other factors. In recent years, scholars have begun to pay attention to the impact of transformational leadership on the formation of corporate strategic flexibility and the role of corporate capability in the "black box" mechanism of corporate performance.Based on the high upper theory, this study introduces strategic flexibility (resource flexibility and capacity flexibility) as the mediating variable to study the mechanism transformational leadership behavior has on enterprise performance in dynamic environment. On the basis of summarizing the existing literature, the research model is constructed and the research hypothesis is proposed. This research uses the combination of questionnaire and second hand data to collect data. To ensure the reliability of the research data, in the measurement of transformational leadership, strategic flexibility and dynamic environment variables, the maturity scale of scholars at home and abroad were used. Through the test by means of "back translation" and pretest in the EMBA students, a formal questionnaire eventually formed. Enterprise performance is assessed through year-end total assets profitability (ROA).Control variables include enterprise age, enterprise assets (logarithmic to the number of employees), the proportion of state-owned shares, corporate asset-liability ratio and industry (divided according to the China securities regulatory commission (CSRC) industry standard, the sample companies come from 15 industries, expressed in 14 virtual variable sample enterprise industry). This study commissioned a third-party consulting company to conduct a questionnaire survey on the senior management team members of listed companies in Beijing, Shanghai, Guangdong and other regions according to the design and requirements of this study, and 208 valid samples were finally obtained.Before data analysis, Cronbach's coefficient was used to test the reliability of the study variables, and confirmatory factor analysis in the structural equation model was used to test the scale's structural validity. The test results show that the scale of transformational leadership behavior and its dimensions, strategic flexibility and its dimensions, and environmental dynamics have good reliability and discriminative validity. Correlation analysis also shows that there is a strong correlation among the variables in this study, and without collinearity problem. In this study, SPSS statistical software was used to test the research hypothesis, and the conclusions showed that :(1) Strategic flexibility plays a full mediating role in the relationship between transformational leadership behavior and enterprise performance. In a dynamic environment, strategic flexibility, as an "intermediary" capability within an organization, strengthens the competitive advantage of an enterprise by acquiring different resources and improving the utilization rate of resources, thus affects its business performance. This conclusion uncovers the "black box" between individual behavior and corporate performance, and provides a theoretical basis for transformational leadership to enhance corporate performance by developing strategic flexibility in a dynamic environment. (2) In dynamic environment, the influence of transformational leadership on resource flexibility and ability flexibility is enhanced. When the environment is more dynamic, transformational leadership behavior is more conducive to improving strategic flexibility. (3) The relationship between strategic flexibility and enterprise performance is not affected by either high dynamic environment or low dynamic environment. Strategic flexibility is a kind of strategic ability for enterprises to obtain high returns.At present, the research on transformational leadership mainly focuses on the influence of individuals on individuals and individuals on the organizational environment, lacking the research on transformational leadership from the enterprise level. Based on the Chinese situation and the introduction of strategic flexibility, this study discusses the mechanism of transformational leadership on strategic ability from the enterprise level, providing a new perspective to further uncover the "black box" of enterprise performance, and at the same time, providing a theoretical basis for Chinese enterprise management practice. In the process of strategic transformation, the strategic leader should transform the dynamic characteristics of the external environment into positive factors to promote the strategic flexibility of the enterprise and improve the business performance by establishing corporate vision, showing consideration for and caring for the subordinates and creating the organizational atmosphere adapting to the dynamic environment.The shortcomings of this study are as follows (1) This study does not focus on the influence of senior management team members on strategic flexibility. As an important member of strategic decision-making and implementation, the executive team's leadership plays an important role in the formation of strategic flexibility. The formation of strategic flexibility and the improvement of business performance are social results of a long-term interaction between the CEO and the members of the executive team. (2) The data of this study come from multiple industries. In the future, a specific industry (such as manufacturing industry and high-tech industry) can be selected for further study. (3) The sample data of this study is a cross-sectional data. In the future, longitudinal data can be introduced to further verify this influence mechanism.

Key words: transformational leadership, resource flexibility, capability flexibility, firm performance, environmental dynamism