Abstract: Objective Aiming to seamlessly integrate elaborated engineering facilities models and large scale land-scape models as well as to support the sharing and application life cycle of three-dimensional GIS,wepropose a new method to automatically build complex models of engineering facilities using designedparameters.The traditional 3DGIS data model is extended to satisfy the demands for integration andsynchronous updating of geometric models and their related parameters.Finally,the validity and fea-sibility of this method are demonstrated through its application for bridge modeling.The proposedmethod facilitates seamless integration of GIS and CAD.