This paper discusses the subject structure and selection strategy in policy evaluation from an independence perspective. The framework for independence inspection consists of five elements: administrative subordination, resource dependence, evaluation sponsorship, the way of contract award, and early involvement in the policy process. Using this framework to analyze authoritative policymaking entities, policy research organizations and the general public, we find that each type is not a unified existence, and the complexity of internal structure means different levels of independence for different secondary subjects. The task features at different policy stages, resource constraints and cost/benefit considerations constitute the contextual attributes of policy evaluation. The combination of subject structure and contextual attributes forms the selection strategy of policy evaluation from the perspective of independence, including the internal requirements for independence, selection order for policy evaluators and other considerations. The emphasis on independence in policy evaluation in Western countries is more out of the logic of party politics, while in China it is mainly out of rationality and science.Adhering to the principle of independence in policy evaluation should be regarded as a demonstration of institution confidence.