Virtual Geographic Environment (VGE), or Geographic Virtual Environment (GeoVE) is considered to have the potential to extend the power of geographic information visualization methods. As the increasing development of computer network and Internet technologies, Distributed VGE (DVGE) has been developed to support multi-users to participate and share the same virtual geographic workspace. Nowadays, more and more tasks require group work, and many of them are spatial related, although DVGE extends the scope for participants to handle geographic problems, it still lacks efficient mechanism to make peoples' collaborative work more efficient. In this regard, we integrate CSCW and AI with CVGE and bring forward Collaborative VGE (CVGE) to support collaborative work in VGE. This paper illustrates the seven distinguished features of CVGE as a criterion for CVGE system design and assess; then analyses the construction of CVGE on the aspects of Individual, System and Society; the construction graphic shows that the perception model, behavior model and collaboration model are the key ingredients of a CVGE system. As an application of CVGE, a collaborative Virtual Forest Environment (VFE) is introduced in which VRML, Agent, Electronic Whiteboard and other technologies are applied.