Abstract: First, a view that the construction of digital city is to turn from providing "data service" to offering "applicalion service" was proposed, and two aspects of "application service" were given, which is information services oriented to the public and the professional fields, respectively. `hhen, for the second aspect that has been studied less than the former, a model service system that is a part of the application service platform of digital city was designed. The role and functions of the model service system in the platform were discussed, and some critical characteristics of the system, ineluding the structure, the model interface specifications, and the workflow to use it, were analyzed. Lastly, the system prototype was presented and its development status was given.

Key words: Digital city, Model service system, Model service,Model integration