The important key to success of environmental education is to realize space and situation where people of diverse backgrounds can universally participate in environmental education and can mutually exchange their candid opinions and practical experiences. Our system, DigitalEE, is designed and implemented to pursue universality of participation in environmental education with the concepts of digital cities. Learners in real forest, environmental specialists in laboratories, and virtual tourists at homes or hospitals can make interactive real-time communication via online 3D virtual nature generated by DigitalEE. Information available via the 3D virtual nature is continuously updated at participants’ own free will, and is used as communication contexts at participants’ discussion on environmental issues. DigitalEE creates an original form of public participation in digital cities such as collaborative interaction between real and virtual worlds, and makes realization of digital environmental education: a future style of environmental education in dynamically changing virtual environment.