One important advantage of Geographical Information System (GIS) is its spatial analyses. According to researches and applications

the best way to implement the spatial analyses is to use the tool of model. However

many GIS systems lack spatial model base in different degrees

which in a sense constrains the spatial analysis ability of GIS. But different from common models

the spatial models must cope with and operate complex spatial data that bring many specific difficulties. So the development of spatial model is very slow compared with that of GIS applications and the related requirements. Introducing the COM technology

this paper studies the reusable spatial model base that is independent to specific applications. Then

based on the study a model base frame is advanced and its implementation is discussed. Our study shows that introduction of COM technology into GIS spatial model base

not only can enhance the reusability of GIS software

but also can help the realization of GIS spatial analyses. Because of the complexity brought by the spatial data

more issues remain to be further studied.