Abstract:    In recent years, with the increasing uncertainty of the market environment, the acceleration of technological updating, the escalation of trade frictions between China and the United States, disruptive innovation has become increasingly important for Chinese enterprises to achieve transformation, upgrading and development. Unlike sustaining innovation, disruptive innovation is a form of change that “disrupts the established trajectory of performance improvement or redefines performance”. It deviates from the existing development trajectory and launches products or services that have poor traditional core performance based on the needs of low-end and new market consumers. Subsequently, it continuously improves performance, ultimately eroding the mainstream market. This market-oriented innovation model not only helps latecomers who lack resource accumulation to achieve leapfrog development, but also promotes the emergence of emerging industries and solves practical problems in social development. However, many enterprises in China currently find it difficult to identify opportunities for disruptive innovation, significant original achievements are still lacking, and many industries are at the low and middle ends of the global value chain. Therefore, how to identify disruptive innovation opportunities and promote their success is not only a practical problem that needs to be solved urgently for enterprise development and industrial transformation, but also an important topic for innovation strategy research.However, some gaps still remain in the existing research on disruptive innovation: firstly, the key to successful disruptive innovation is the timely identification of and response to windows of opportunity, and the challenge of legitimacy for disruptive innovation must be addressed in order to successfully respond to windows of opportunity, but the existing literature on disruptive innovation has not systematically examined windows of opportunity and legitimacy. Secondly, research on responses to windows of opportunity has focused on the firm level, neglecting the active shaping role of government at the cultural and cognitive levels. Therefore, this paper integrates opportunity windows and legitimacy into the study of disruptive innovation processes, and takes Shengzhou′s integrated stove industry, a typical case of successful use of disruptive innovation to achieve transformation and upgrading, as the object of study. It intends to explore the sources of opportunity windows for disruptive innovation and strategies to promote the identification and response of opportunity windows, with a view to providing inspiration and reference for the transformation and upgrading of regional industries.Through the case study of the integrated stove industry in Shengzhou, this paper revealed how enterprises and governments identify and respond to the window of opportunity of disruptive innovation. The main research conclusions were that windows of opportunity for disruptive product innovation arise from two performance realization options: changing a product′s single performance module and switching the way it is structured between modules; the identification of windows of opportunity for disruptive innovation is facilitated by factors such as firms′ technological ambitions and network synergies, and the continued identification of windows of opportunity is further ensured by government brand awareness and resource support; regional companies can use "functional inspiration-emotional construction-emotional enhancement" strategy to gradually establish normative and cognitive legitimacy. Regional government can use the strategy of "standard construction-government legitimacy spillover-platform legitimacy spillover" to promote the rapid transition of regional industries from the low-end to the mainstream market.This paper further enriched the study of disruptive innovation by exploring the process of disruptive innovation in regional industries and identifying the strategic role of government in cognitive shaping and meaning making. On the other hand, it identified the legitimacy issues in unique contexts, and it explored how firms and governments can adopt relevant strategies to address legitimacy issues in the disruptive innovation process. It will provide inspiration and lessons for regional government and business practice.

Key words: disruptive innovation, window of opportunity, legitimacy, regional industry