Abstract: This paper explains why the environmental aspects of geotechnology urgently need to be evaluated. Also discussed is why the current approach in geotechnical engineering is not effective for studying the soil-environment interaction. Refinement of particle-energy-field theory proposed in late 1980’s by the author is made with special emphasizes on the applications to sensitive ecological geotechnology, such as: (1) mechanisms of wet-dry, swell-shrinkage and freeze-thaw cycles of soil; (2) soil contamination and decontamination mechanisms and processes; (3) controlling the radioactive nuclear wastes and radon gas. Finally, two most challenging environmental geotechnical projects as examples are used to illustrate how interdisciplinary and complex nature of environmental geotechnical problems will be.