Agent technology is applied into constructing distributed GIS. A distributed GIS-oriented multi-agent system named as Geo-Agents is designed and implemented. Firstly, the classification, structure and features of agent in distributed GIS are analyzed. There are four types of GIS Agent: system management agent, GIS function agent, interface agent and GUServer. Every GIS Agent is a synthetic entity that consists of control subsystem, functional subsystem, communication subsystem, human-computer interface and data resource, and every GIS Agent is determinate, independent, autonomous, interactive and initiative. Secondly, a message mechanism is used to provide communication and coordination between GIS Agents, and a set of Geo-Agents message types are designed according to the properties of GIS and Agent. After that, the architecture and network distributed model of Geo-Agents are proposed. At last, two sample uses of Geo-Agents are explored: agent-based spatial information navigation and spatial decision-support system.