This study develops a comprehensive evaluation framework to assess the incorporation of river ecosystem services (ESs) into policy content, focusing on China's River Chief System (RCS) policy. The framework introduces a quantitative tool that bridges the gap between policy formulation evaluation and policy effect evaluation by integrating a hierarchical indicator system, reference values, and a method for quantifying ES incorporation. Key findings from 32 province‐level RCS policy documents revealed selective incorporation of certain ES indicators, significant mismatches between policy focus and the typical structure of river ESs, and notable regional disparities. Provisioning services (i.e., water supply) and regulating services (i.e., pollution mitigation) are prioritized, while critical regulating services (e.g., flood mitigation and habitat maintenance) and cultural services (e.g., education and science) are underrepresented. Stakeholder and relationship indicators are limited, primarily focusing on managers and spatial relationships, while the value of river ESs is largely ignored. Policy optimization should emphasize expanding the coverage of ESs, incorporating broader stakeholder involvement, and integrating financial incentives. Drawing on international river policies, policymakers could create a more flexible and adaptive river governance structure. While the study offers a quantitative framework for policy evaluation, it acknowledges limitations, including reliance on textual data and potential biases in the reference values. Future research should include stakeholder perspectives and dynamically adjust reference values as new data become available.