Abstract: During the past 100 years a great success for the mankind is the earth observation from space.We can remotely and automatically observe and measure our planet,by non-contact sensors from air and space.The geospatial data and the geographic information obtained and extracted by remote sensing can be stored on wire and wireless computer network and then utilized by different users for social sustainable development and human living quality improvement.As a new cross-discipline,remote sensing and GIS have become a science,technology and economic body andFK(W30。40ZQgrown up very fast in the past 30 years.What is the tendency and trend of RS and GIS in the 21st century?The author will illustrate his vision in this paper.There are at least six development trends in remote sensing:·Data acquisition of airborne and spaceborne RS will be multi-platform,multi-sensor and multi-angle with high resolution.·Determination of 3D coordinates for RS objects will be less dependent upon ground control points,even without GCP.·Image processing for remotely sensed data by using modern computer techniques will be more automatic and more intelligent.·Automatic change detection by using multi-temporal data including image data and existing GIS data will be done in real time and even in orbit by using smart sensors.·Airborne and spaceborne RS will play more and more important role in the construction of "Digital Earth","Cybercity" and "Digital Culture Heritages" and so on.·Fully quantitative solution of RS including geometric and physic equations will be investigated step by step and applied smoothly from theory to practice.For GIS there are five main development trends as follows:·Spatial databases will be object-oriented and unified with DLG(digital line graphics),DOQ(digital orthophoto quadrate) and DEM(digital elevation models).·Representation of spatial data will be multi-scaling,multi-dimensional and dynamic by using 3D visualization and visual reality methods.·Spatial data mining and knowledge discovery will be thoroughly studied and used for improving intelligent level of GIS spatial analysis and for supporting decision making.·MLS/LBS techniques through Web/WAP servers will promote GIS to be geo-information service for anybody and anything at anyplace and anytime.In this case federal databases and interoperability will be solved in near future.·Research on geographic information science will build its theoretical framework in the 21st century.The above-mentioned topics are discussed in this paper.