摩尔比法是最常用于吸光光度法测定络合物组成比的经典方法之一 ,优点是实验简单。它是Ｙｏｅ和Ｊｏｎｅ在 1944年提出的[1],但是当初并无理论上的证明。后来不少人都做过论证[2～ 5],但未能很好地解释曲线形状 ,也未讲清楚作图的依据。本文从溶液中络合物的离解出发来解释曲线 The molar ratio method is one of the most commonly used classical methods for the determination of the complex composition ratio by spectrophotometry, with the advantage of simple experimentation. It was proposed by Yoe and Jone in 1944 [1], but was not theoretically proven at first. Later, many people have argued [2 ~ 5], but failed to explain the shape of the curve well and did not make clear the basis of the mapping. This article explains the curve from dissociation of complexes in solution