首先简要回顾“场”与“路”的基本内容，从基本体系上进行比较并列出二者物理量关系.然后从电磁学中电路抽象角度阐明“场”衍生“路”的建模方法及“第四类”基本无源元件演绎.最后，给出的应用实例———生物组织检测的共振光声光谱.

This paper firstly reviews the basic content of“field”and“circuit”，compares them from the primary structure and lists the relationship between the two physical quantities. Then，from the perspective of circuit abstraction in electromagnetics，it clarifies the modeling method of“field”derivative“circuit”and“Fourth class” basic passive components deductive. Finally，the application example is given: the resonance photoacoustic spectroscopy of biological tissue detection.