With information and networking age approaching, people require higher and higher educational quality.Well-designed modern distance educational environment can make up for the disadvantages in traditional distance education where there were communication difficulties due to time and physical space. The article putsforward a series of design principles including design of technical environment of human resources, that ofinstructional software, that of learning support system and that of distance educational network. The author also elaborates on how to make these into a unified and collaborative system.