中文摘要：

多粒度方法是粗糙集理论中的一种新的数据处理模式。为了使多粒度方法适用于不完备信息系统，在相似关系的基础上，提出了基于集值信息系统的多粒度粗糙集模型，包括乐观和悲观两种不同的形式，不仅分析了两种模型的基本性质以及它们之间度量的关系，而且研究了决策规则获取的方法。最后将基于集值信息系统的多粒度粗糙集应用于信息系统安全审计风险判断，为信息系统安全审计的有效判断提供决策支持。

英文摘要：

Multi-granulation approach is a new analyzing model in rough set theory.To deal with the in-complete information system through the multi-granulation approach,on the basis of the similarity relation, multi-granulation rough set model based on set-valued information system is proposed,which includes optimistic and pessimistic cases.Moreover,not only the basic properties and measure relations of two kinds of multi-gran-ulation rough sets are analyzed,but also the acquisition of decision rules is presented.Finally,this model is ap-plied to risk judgment on security auditing of information systems,and it can provide decision support for effec-tive judgment on security auditing of information systems.