Embedded in the formal system of the company as an informal organization, factions of board influence the strategic decision and policy implementation. This paper uses the data of A-share listed companies in Shanghai and Shenzhen to study the influence of the board factions measured by faultline on the strategic change of enterprises. Our study found that the board ability faultline has a positive effect on the company strategic change, while the board identity faultline has a negative effect on the strategic change. Further research found that the depth and width of board experience promotes the positive influence of the board ability faultline and alleviates the negative influence of the board identity faultline, by strengthening the organization"s ability and resource base to implement strategic change. Second, the board turnover rate can effectively prevent the interest alliance of the board ability subgroups and the escalation of conflict among the board identity subgroups, and promote the positive influence of the board ability faultline and weaken the negative influence of the board identity faultline. Third, the uncertainty of economic policy promotes the positive influence of the board ability faultline and alleviates the negative influence of the board identity faultline, by prompting subgroups to reverse their positions, from internal differences to external unity, with identity gap alleviation and task interaction enhancement. Last, compared with local state-owned enterprises, the board faultline of central enterprises has no significant influence on the strategic change. The conclusion of our study reveals the double-sided governance effect of board faction to the major strategic decisions, deepens the understanding of the board structure and decision-making interaction mechanism, and provides evidence for optimizing the staffing of the board.Keywords：Factions of Board; Board Faultline; Strategic Change; Subgroup interaction.