Since the Digital Earth been advanced by Al Gore—the vice presidentof USAon Jan.31 1998
the scien tists
entrepreneurs and politicians of many countries have responsed activelytoit
they allproposed a digitalearth from their own pointofview
butallofthem didn’tgive a system and overallvision .Based onthe developmentofgeographic information processing and information technology and the requirement of information society
a system and relatively overall description ofdigitalearth is given inthis paper
the research contents
keytechnologies and application prospect are covered .In this way
a relatively objective description of digitalearth is given .