Since the 1990s, influenced by the new public management movement and profound changes in the global academic labor market, the American model of academic appointments, particularly the tenure system, has been diffusing to other countries and regions. This diffusion demonstrates a convergence in core system principles while diversifying in its forms. The unique traditions in higher education governance and legal regulations across countries, the legal standing of university teachers, and variations in academic labor markets contribute to the complexity and diversity of reforms in the academic appointment system. Germany, for instance, has pursued a top-down reform approach led by the government through legislative regulations. China, on the other hand, has adopted a reform approach involving government-university interactions, blending independent explorations by colleges and universities with national policy endorsement amidst institutional reforms. After attaining the status of independent legal entities, Finnish universities have initiated bottom-up reforms in their personnel systems to enhance international competitiveness. However, in the process of adopting and diffusing these new personnel systems, countries often encounter complex legal risks and conceptual conflicts. Balancing tradition and modernity, professional autonomy and managerial oversight, and job security and performance competition, and integrating new personnel systems into specific national governance and legal frameworks are crucial challenges in reforming academic appointment systems.