The purpose of M&A usually directs to the exploration of business scale and the decrease of operation cost. The post-merge integration not only emphasizes on the integration of business unit to increase the profit, but also on the centralization of supporting lines regarding similar function, in order to decrease the duplicated cost of workforce. Most of the research papers focus on the performance of M&A or the integration manners of business unit, however, few of the research points out how the supporting lines integrate with each other. Thus, this report intends to figure out the key points of the centralization of supporting lines thorough the integration of human resource division. The practice of the case study reveals that the success of the integration relies on the determination of senior management, which helps to facilitate the execution part. Meanwhile, the similarity of the operation process within the subsidiaries also contributes to the success of the integration. However, the failure of the integration results from the characteristics of the different industries and the resistance of the subsidiaries¡¦ HR managers rather than the issues concerned by the senior management or the project execution.