随着数字城市建设的全面开展，地理信息以在线服的方式实现的应用和共享得到社会各行各业越来越的支持和认可。构建数字城市地理在线服务系统，为政府部门和社会公众提供实时、稳定的信息服务，促进信息资源的广泛应用，已成为一项必要工作。 由于传统GIS应用系统存在对数据操作性弱、数据共享性较差以及数据访问运行效率较低等因素。作为服务型GIS——NewMap能够很好地解决这些问题，并满足各类用户的需求。本文以陕西省榆林市部分地理信息数据为例，利用New Map软件进行数字城市地理在线服务二次开发，主要研究内容和结果如下： （1）深入分析了数字城市地理在线服务建设的相关理论和支撑技术，探究国内外数字城市发展状况，就相关技术进行详细探讨分析。SOA技术方便灵活的实现系统的集成，NewMapAPI技术提供的接口能够高效、快速的搭建地理信息应用程序，地图缓存技术降低服务器负担，提升地图浏览速度效果等。 （2）本文根据服务需求和目标分析，研究基于NewMap的数字城市地理在线服务平台的架构设计，提出了“支撑层、数据层、服务层、应用层”四层结构设计方案。 （3）本文在线服务系统主要针对登陆注册、基本地图操作和功能操作三大模块进行 详细分析并设计开发，实现了地图基本操作、地理要素查询、统计分析、地图标注和地图加载等功能。

With the spread construction of digital city，application and sharing of geographic information to an online service to achieve all walks of life more and more support and recognition. It has become a necessary work that constructing a digital city geographic online service system to provide real-time, stable information services for government departments and the public to promote the wide application of information resources. Because the traditional GIS application system exists some factors，Such as weak data interoperability，Poor data sharing and low data access efficiency. The service-oriented geography information system of NewMap can effectively solve these problems, and meet the needs of various users . This paper takes part of geographic information data Yulin city of shaanxi province as an example, uses the New Map software for digital city geographic service online secondary development. The main research contents and results are as follows: (1) This paper deeply analyzed the related theory to the construction of digital city geographic online services and supporting technologies, explored digital city development situation at home and abroad and related technologies are discussed in detail. The technology of SOA to realize system integration, NewMap API technology provides interface to build efficient and fast application of geographic information, and the map cache technology can reduce the burden on the server, improve map browsing speed effect and so on. (2) According to the needs and goals of service analysis, this paper researches framework designs of NewMap-based online service platform of digital urban geography, proposes a structure design which has four-layer structure :support layer, data layer, service layer and application layer. (3) This article focused on three modules for detailed analysis and design and development, which is landing registration, basic map operation and functional operation. The basic operation of the map, geographic features query, statistical analysis, marked maps, and map loading. It implements the basic operations of the map, geographic feature query, statistical analysis, map labels and maps loading, etc.