中文摘要：

保守扩充是数理逻辑中一个重要的性质。本体的保守扩充在本体设计和本体集成中扮演重要的角色。它可形式地精练本体、可靠地进行本体合并及在本体内部进行本体模块化。在本体的进化和本体的合并中，保守扩充最基本的任务是判定合并后的本体是否是原始本体的保守扩充，如果不是，那么进化后的本体与原始本体将不能保持一致的逻辑结论。分析了现有的描述逻辑的保守扩充及其相应的判定算法，提出描述逻辑VL的保守扩充，并构建了VL的典范模型，证明了VL的保守扩充的判定算法是指数时间复杂的。

英文摘要：

The conservative extension is an important property in the mathematical logic.The notion of a conservative extension plays aeentral role in ontology design and integration ,it can be used to formalize ontolo-gy refinements,safe mergings of two ontologies, and independent modules inside an ontology. Regarding reason-ing support, the most basic task is to decide whether one ontology is a conservative extension of another.If this is not the case, then the evolution of the ontology with the original ontology will not be able to maintain the same logical conclusion.The current research works of conservative extension and its algorithm in description logic is analyzed in this paper.