在计算机科学中，求值策略(Evaluation strategy)是确定编程语言中表达式的求值的一组（通常确定性的）规则。重点典型的位于函数或算子上——求值策略定义何时和以何种次序求值给函数的实际参数，什幺时候把它们代换入函数，和代换以何种形式发生。经常使用用来研究函数的形式系统λ演算来建模求值策略，这里它们通常叫做归约策略。求值策略分为两大基本类，严格的和非严格的，基于如何处理给函数的实际参数。一个语言可以组合多种求值策略；例如C++组合了传值调用和传引用调用。多数语言对布尔表达式和if语句使用某种形式的非严格求值。

A programming language uses an evaluation strategy to determine when to evaluate the argument(s) of a function call (for function, also read: operation, method, or relation) and what kind of value to pass to the function. For example, call-by-value/call-by-reference specifies that a function application evaluates the argument before it proceeds to the evaluation of the function's body and that it passes two capabilities to the function, namely, the ability to look up the current value of the argument and to modify it via an assignment statement. The notion of reduction strategy in lambda calculus is similar but distinct.