ＩＳＮｅｔ（独立自旋偶合网络，ＩｎｄｅｐｅｎｄｅｎｔＳｐｉｎＣｏｕｐｌｉｎｇＮｅｔｗｏｒｋ）是作者为了严格地从多维ＮＭＲ谱推导出溶液状态中复杂有机物的分子结构而建立的新概念。从数学上讲，ＩＳＮｅｔ可被视为分子结构连接性的另一种表达形式，是一种图论表达。与分子结构图的共价键表达不同之处在于，ＩＳＮｅｔ中的每一条边在理论上是二维ＮＭＲ谱图上的一个可观察的峰。本文建立ＩＳＮｅｔ概念，并讨论从实验波谱，运用ＩＳＮｅｔ分析理论导出各类分子结构的原理及其图论、模糊数学基础。 ISNet (Independent Spin Coupling Network) is a new concept developed by the author to strictly derive the molecular structure of complex organic matter in solution from multidimensional NMR spectroscopy. Mathematically, ISNet can be thought of as another form of representation of molecular structural connectivity, a kind of graph theory. Differing from the covalent bond representation of molecular structure diagrams is that each edge in ISNet is theoretically an observable peak on a two-dimensional NMR spectrum. In this paper, the concept of ISNet is established and the theory of deriving various molecular structures from experimental spectrum and using ISNet analysis theory and its theory of graph theory and fuzzy mathematics are discussed.