3S is the collective description of three new high technologies-GIS (Geographic Information System), RS (Remote Sensing), GPS (Global Positioning System). And VR means virtual reality. Nowadays, 3S and VR technologies are widely used in many fields. With the development of technology, the application of 3S and VR technologies in traditional fields of environmental science and engineering has already been prevalent. In the environmental planning of Changsha eco-city development as nationwide demo-city, we attempt to apply these two advanced technologies. This paper mainly represents how to make the best use of 3S and VR technologies in the environmental planning for Changsha eco-city and offers some measures to settle existing problems. At the beginning of this paper, the disadvantages of traditional ways and the advantages of 3S and VR technologies in environmental planning are both analyzed, and the principium in the operation is presented. After that, this paper reveals 3S and VR technologies' function and relations with other systems in the environmental planning for Changsha eco-city, and then expatiates the operating methods in detail. In the introduction of applied methods of 3S technology, the functions of GIS and the processing methods of environmental information from point, line and polygon sources are emphatically narrated with some typical cases. In the introduction of applied methods of VR technology, this paper discusses two ways to construct virtual environment: geometry-based virtual environment and image-based virtual environment. The characteristics and applicability of the two ways are compared, and some operating hints are also given. In the end, this paper draws some conclusions: 3S and VR technologies have powerful functions in collection, management and embodiment of environmental information. And it can be deduced that they have great recommendable value and cheerful using prospect not only in environmental planning but also in the whole field of environmental science and engineering.