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.