配位化合物中不少先前被认为是简单的１∶１配合物，而实际上却是多核配合物，原因是它们的组成比相同，都是１，因而多核配合物的存在不易被发现目前已有数种方法可以识别并可测定其稳定常数，如图解偿试法，但计算较繁琐本文基于直接测定配合物吸光度建立一种新的图解法，不需通过偿试而后测定多核配合物组成和稳定常数，实验与计算均较简单，试用于Ｆｅ（Ⅲ）ＥＣＲ或ＣＡＳ体系，获得了满意的结果 Many of the coordination compounds were previously thought to be simple 1: 1 complexes, but in fact they are polynuclear complexes because their compositional ratios are both 1, so that the presence of polynuclear complexes is not readily detectable There are several ways to identify and measure the stability constants, such as the graphical method, but the calculation is more complicated  This article based on the direct determination of the absorbance of complexes to establish a new graphical method, without going through the test and then determine the composition of multi-core complexes And stable constants, the experiment and calculation are relatively simple, and they are satisfactory for Fe (Ⅲ) ECR or CAS system.