Lots of knowledge can be discovered from GIS database. Knowledge discovery from database of GIS has been drawing more and more attentions in different fields such as geo-science field

and computer field. ESDA technique especially emphasizes the study on the spatial dependency and spatial heterogeneity. And it is used to preliminary discover some law hidden in the data sub-aggregate of interest in the field of knowledge discovery. It is one of the most important contents to some normal whole and local spatial statistics including Moran I

Geary C

G statistics

LISA and so on. And it is the key of making ESDA technique and GIS completely and closely integrated to fully make use of GIS visualization and spatial analysis technique under the condition of imperfect Expert System. The example

which is China floating population’s spatial distribution law discovered from GIS database

shows the method and steps to discover knowledge from database of GIS with the integrating ESDA and other knowledge. The results show that it is practical and effective to discover knowledge from from GIS database with ESDA. But it is impossible to completely and automatically discover knowledge from GIS database and other synthetic knowledge must be integrated into the course of knowledge discovery. The method of knowledge discovery in the paper is used in the mode of man-machine conversation and it needs urgently to be supported by Expert System.