This paper addresses several key issues for digital earth oriented virtual reality system

with multi layer scene engine (MLSE)

view dependent dynamic multiresolution terrain model(VDDMTM)

ActiveX component based network model discussed. By means of scene layer

MLSE enables multi variates integration

scene rendering and user interaction. Quad tree structure is used for multi resolution terrain representation. View dependent terrain simplification and multi resolution texture mapping are applied to keep ROI(Region of interest) details and accelerate rendering. Client/Server based ActiveX network model not only meets specific needs for geo data modeling

but also well supports WWW browsers. Based on above research

a prototype system

virtual earth system(VES)

was developed to visualize YongDing River and Mountain Himalayan.