The profession of engineering geology provides knowledge and methods to cognize the regulation and course of the interaction between engineering and geology. Its task is to guarantee the safety of engineering activity of human beings. Its essential theories include (a) geology of origination and evolution, (b) domination of geological structure, and (c) interaction between engineering and geology. These three theories have the similar thinking process that the origination determines the structure, the structure dominates the behaviors. Engineering geological process is actually a process of interaction between engineering and geology. At present, engineering projects have become larger and larger and deeper and deeper and their encountered geological conditions have become more and more complicated. Consequentlyengineering geological problems present new features and its objects have become remarkably large, deep, dynamic and high temperature. Coupled actions among fluid, stress, temperature and chemistry have challenged the exist theories that were developed for relatively simple ground conditions. Research on engineering geological process should be further extended. Further combination among geology, geophysics, mechanics and engineering sciences is believed the most effective approach. Paying equal attention to theory, technology and practice is the basic mode for the further development of engineering geology profession.