根据石墨的形态特征，运用物元分析方法建立起关于石墨形态识别的物元模型，提出了可拓分类树方法，讨论了可拓分类树的构造和实现途径，并将其应用于石墨形态的类型判别；给出了典型的实验结果，并对该方法与现有识别方法作出比较。

The basic types of graphite morphology in nodular cast iron is introduced. According to the graphite morphological features, matter-element analysis theory is applied to establish the matter-element model for graphite morphology recognition. In this paper, extension classification tree is proposed. The way of construction and realization of extension classification tree is given. Extension classification tree is used to identify the graphite morphology. The typical experiment results are given. The method is compared with other current recognition methods.