Abstract: In this paper,a geo-rough space was proposed as a new approach to handle spatial entities in data analysis.And its basis was rough set.In the geo-rough space,the set of symbols from rough set are simplified and standardized,which includes both rough interpretation and specialized indication.The boundary set was used to take the place of the upper approximation in a practical computation and decision-making.The geo-rough space was characterized by rough entities,rough relationships and rough algorithms in spatial discourse universe,whose element was rough element with a rough degree to measure the roughness.This paper discussed it in Geomatics,paying more attention to the computerized GIS.The result of the case study on thematic image extraction indicated that the geo-rough space was confidential and practical.