W3C established the eXtensible Markup Language standard format (XML 1.0). The eXtensible Markup Language (XML) is widely used as the de facto standard for data representation and exchange on the Internet and Intranet. Discover frequent sub-pattern from semi-structured dataset is a hot research topic. This paper proposed a method to discover maximal Conspicuous Changing Substructures (CCS) from dynamic XML documents dataset. The authors proposed the TDOM model, the TDOM model record the historical changing process for XML data. Then, they proposed the definition of CCS and proposed the method to discovery CCS from dynamic XML document collections. The experiment result shows that their approach is efficient.