Earth Observation and application is one of the core missions in space technology development. Up to now, over thousands of spacecrafts have been launched, and earth observation satellites occupy a very important position. It has become an area of no substitute, which can bring profit to economic development, national security and demands on environment and resources. The development over decades shows that earth observation technology has become a strong trend around the world. In China, earth observation Technology started from 1970s. Up to now, it has developed over four stages and has acquired considerable scale in the technology system, which spans the spectrum and achieves considerable development in data collecting. Besides, the application is expanded and in-depth basic research and processing methods have been set up. In the National Long-Term Technology Development Program, there are severalimportant items and research projects relevant to earth observation. In China, earth observation technology will abide by the principle of “Demand Pulls, Technology Pushs”，aiming at coming up with international advanced technologies.