城市是社会经济的中心，国内生产总值的80%集中在城市，我国近年来提出了农村城市化的倡议，城市化已经成为社会发展的大趋势，城市在我们整个社会的地位越来越突出。当今的城市已不仅仅是一个人类集聚地而已，城市已经成为一个有机的整体，因此我们要利用科技来变革城市，在这种情况下，作为数字城市实现手段的城市三维地理信息系统应运而生。近年来，数字城市逐渐成为人们关注的热点，而城市三维地理信息系统作为数字城市的一个重要组成部分，已经成为当今测绘领域的工作重点。 本文从数字城市的理论出发，构建了朝阳新区城市三维地理信息系统，此系统可以为用户提供不同用途的三维地理信息服务，为城市管理部门提供现阶段城市发展情况的参考依据，并可为城市规划管理部门提供决策参考；它为朝阳新区建立了地理空间数据库，方便用户查询各个单位的属性数据；它同时可以给用户提供综合地理信息服务，包括浏览城市景观、进行各种生活所需的三维分析、查询所需信息等。 本文从构建城市三维地理信息系统的角度出发，依据地理信息系统开发的原则，确定了建立城市三维地理信息系统的技术和方法，以航摄影像、数字高程模型和地形图为基础，建立了朝阳新区三维场景，利用C#.net编程语言，采用skyline软件提供的TerraDeveloper组件作为开发平台建立了三维地理系统，主要实现三维基本操作、信息查询、空间分析和三维漫游等功能。

City is the center of socio-economic, 80% of Gross Domestic Product (GDP) is concentrated in city，China put forward the initiative of rural urbanization in recent years, urbanization has become a big trend of social development , the city's position has become increasingly prominent in our society . Today the city is not only a human gathering place but an organic whole, so we have to use technology to change the city, in this case, the three-dimensional geographic information system came into being as the Means of realization of the digital cities. In recent years, the digital city is becoming the focus of attention, while the city's three-dimensional geographic information systems as an important component of the Digital City, has become the focus of the work of the surveying and mapping. I built Chaoyang New District Three-dimensional geographic information systems from the theory of the Digital City, this system can provide users with different uses of three-dimensional geographic information services, and provide urban management department with the urban development in this stage as a reference, and provide decision-making for the city planning and management department; I built Chaoyang New District geospatial database, users can query the attribute data of each unit conveniently; It also can provide users with comprehensive geographic information services, including browsing the urban landscape, various three-dimensional analysis, query the information you need. In this paper I determine the technology and methods of geographic information systems,from the perspective of building the city's three-dimensional Geographic Information System and in accordance with the principles of geographic information systems development, based on aerial photos、digital elevation models and relief map, I establish the Chaoyang New District Three-dimensional scene, in this paper I use C#.NET programming language and the development platform three-dimensional geographic component TerraDeveloper skyline software provides, the system is mainly to achieve three-dimensional basic operations, information query, spatial analysis and 3D roaming and other functions.