具有分布式计算能力是新一代WebGIS平台的主要特征，为了使人们对分布式WebGIS有一个概略了解，首先提出了基于COM 的分布式WebGIS(DWebGIS)的组织策略及实现方法；然后对DWebGIS的架构及COM 的地图服务引擎进行了分析，并讨论了DWebGIS系统中的分布式设计和处理方法；接着详细论述了服务器集群网络负载平衡、无状态对象隐藏标识、及时激活(JIT)和对象缓冲池等DWebGIS系统的关键处理技术，此外，还对基于地图图像的客户／服务器对象操作方法、地图文件命名“三因子法”及系统的“请求／响应”机理进行了较深入的阐述；最后通过在浙江省数字流域治理规划管理系统的应用实例，验证了基于COM 的DWebGIS系统设计的正确性和可行性。

The ability with distributed computing is a main characteristic for new WebGIS platform. An organizing strategy of distributed WebGIS (DWebGIS) based on environment of server group and its implementation are presented. Then the distributed architecture of DWebGIS and engine of map services for COM+ were analyzed in detail. A distributed solution and process methods about DWebGIS are discussed, in which network load balancing (NLB) of server group, hidden marks of no-status objects, just-in-time (JIT) activation and object pooling are the key technique. Also, process of image based map-entities-objects in Client/Server, "three factors" (The alone file- name are created by SessionID、server systematic time and random number), cycle of system request/response are expatiated on. Lastly, the correctness and feasibility for design of WebGIS system platform based on COM+ technique are proved by an example in Zhejiang Provincial Digital Drainage Area Planning System. Our further R&D work is in progress.