Abstract: This paper gives method of multi-layer use case modeling and duty-based multi-layer analysis modeling with UML.Generally speaking,methods with UML to develop GIS use one-fold use case diagram and event flow document to describe use case model in requirement capture phase and use one-fold class diagram to describe analysis model in analysis phase,which lack methods distilling class.This will make us cannot clearly and comprehensively describe question space and make the design ambiguously.Using package and extended mechanism in UML,adopting improved method of multi-layer use case modeling in requirement capture phase and adopting improved duty-based multi-layer analysis modeling in analysis phase can meet features of CIS well.