Based on the sort feature of derived CAPP expert system, this paper discusses the basis concept, importance, key steps and realizing of ISODATAand focuses on the criterion and rule of clustering.

• 基于派生式 CAPP专家系统的 GT分类特点 ；论述了ISODATA方法的基本概念、重要性、主要步骤及算法 ；重点介绍了聚类判据与准则 .