This article explores Cambodia's Professional Standards for School Principals (PSSP), focusing on functions and content in fulfilling principals' roles and responsibilities during the ongoing educational reforms. The official PSSP, along with relevant supporting documents from the Ministry of Education, Youth, and Sport (MoEYS) of Cambodia, were analyzed. The documents' priority actions, strategies, and objectives were carefully examined using content analysis. The findings showed that the standards' functions and contents were crucial in supporting and guiding principals' professional roles and responsibilities, ensuring alignment with international and regional standards. However, the standards expressed rigid functions and content, reflecting concerns over local practices under the decentralization reform. Additionally, the standards outlined principals' roles and responsibilities across the five leadership competencies--personal excellence, strategic thinking and change management, managerial leadership, leading learning and teaching and community-based engagement--but some roles have expanded in response to ongoing developments and requirement in education, particularly growing socio-political affairs, integrating digital technology in school system, teaching and learning activities, and increasing external stakeholder engagement. This study illuminated the alignment of standards, policies, and principals' obligations, fostering discussions on improving educational standards in Cambodia and elsewhere. However, this study is sorely based on documents, survey reports, and research articles lacking various triangulation data from stakeholders. Further research should expand the scope of the study on the implementation of the standards and principals' practices and challenges at school levels by using scientific methods.