摘要：China has a huge volume of historical resources on its contemporary history. Lots of valuable knowledge are hidden in those resources and cannot be utilized easily. It is an urgent problem to mine the implicit semantic knowledge scattered in a large number of historical resources and to reorganize the historical knowledge and facts in a fined-grained manner, so that can help user to explore the historical knowledge for research and education. This paper proposes a method, which is called “Mining down, Organizing up”, to semantically represent and organize historical knowledge on contemporary China hidden in historical encyclopedia text. Based on the proposed historical ontology of contemporary Chinese, this method extracts knowledge objects and facts from the unstructured historical text items by utilizing text mining technologies, represents the historical knowledge in semantically enriched way, and interlinks the related historical knowledge objects and facts to form a historical knowledge network of the contemporary China. By mining the historical facts and the historical knowledge network, the authors get more valuable patterns from the historical knowledge which could be used to form the new organization scheme to reorganize the historical knowledge in a more vivid way. Based on this method, the authors developed a system which can represent and organize historical knowledge of contemporary China in a fined-grained manner, support user to explore historical knowledge by providing functions such as semantic retrieval, historical objects and facts clustering, visualization navigation, association analysis, and chronicle facts reconstruction etc.