Abstract: Massive spatial information oriented distributed geographic information system (GIS) is heading the development of Geoscience. Collaboration and parallel are intrinsic features of multi-agent system. An agent-based distributed GIS named as Geo-Agents and consisting of GuServer, facilitator, interface agent and GIS function agent is introduced. Collaboration and parallel modes in Geo-Agents are explored and analyzed in detail. Collaboration is embodied in two aspects：collaboration among interface agents and collaboration under control of interface agent, while parallel is performed by GIS function agent, which is implemented as three modes：isomorphic cooperative parallel, heterogeneous cooperative parallel and mutually exclusive parallel. At last, two collaboration and parallel samples (spatial data navigation and overlay analysis) are given to illustrate the use of Geo-Agents.