The professionalization of social work in mainland China constitutes a paradigmatic case of a state-engineered professional project, strategically deployed to manage the complex social consequences of rapid market reforms and societal transformation. Formally inaugurated by the 2006 Central Committee Decision, this top-down process has been instrumental in constructing a large, credentialed contingent of social work professionals to bolster social governance, innovate public service delivery, and foster social harmony. This chapter provides a comprehensive analysis of this multifaceted development. It begins by excavating the profound historical and socio-political drivers that necessitated the profession’s emergence. It then meticulously traces the policy evolution and institutional mechanisms that established the national professional-level evaluation system, serving as the cornerstone of professionalization. The analysis delves into key legislative documents, including the seminal Provisional Ordinance on the Evaluation of Social Workers’ Professional Levels (2006) and the culminating Senior Social Worker Evaluation Measures (2018), which collectively forged a rigorous, three-tiered (Assistant, Social Worker, Senior) national credentialing framework. Furthermore, the chapter presents a critical review of longitudinal examination data (2008–2022), revealing robust growth in the professional workforce alongside persistent challenges such as acute regional disparities, variable pass rates, and retention concerns. The evidence demonstrates that the professionalization project, underpinned by a deliberate competency-based examination regime, has substantially elevated the quality, legitimacy, and scope of social work services in China, facilitating its integration into global social work discourse. The chapter concludes by delineating future imperatives, including the need for enhanced remuneration systems, the development of indigenized practice theories, and the cultivation of advanced practice leadership to ensure the profession’s sustainable and deep-rooted development.