Background: Evidence briefs for policy (EBP) draw on best-available data and research evidence (e.g., systematic reviews) to help clarify policy problems, frame options for addressing them, and identify implementation considerations for policymakers in a given context. An increasing number of governments, non-governmental organizations and research groups have been developing EBP on a wide variety of topics. However, the reporting characteristics of EBP vary across organizations due to a lack of internationally accepted standard reporting guidelines. This project aims to develop a STandard reporting guideline of Evidence briefs for Policy (STEP), which will encompass a reporting checklist and a STEP statement and a user manual. Methods: We will refer to and adapt the methods recommended by the EQUATOR (Enhancing the QUAlity and Transparency Of health Research) network. The key actions include: (1) developing a protocol; (2) establishing an international multidisciplinary STEP working group (consisting of a Coordination Team and a Delphi Panel); (3) generating an initial draft of the potential items for the STEP reporting checklist through a comprehensive review of EBP-related literature and documents; (4) conducting a modified Delphi process to select and refine the reporting checklist; (5) using the STEP to evaluate published policy briefs in different countries; (6) finalizing the checklist; (7) developing the STEP statement and the user manual (8) translating the STEP into different languages; and (9) testing the reliability through real world use. Discussion: Our protocol describes the development process for STEP. It will directly address what and how information should be reported in EBP and contribute to improving their quality. The decision-makers, researchers, journal editors, evaluators, and other stakeholders who support evidence-informed policymaking through the use of mechanisms like EBP will benefit from the STEP.