Abstract: Geoengineering is a new growing geology since 1980s and becomes a new discepline ofengineering geology and a new vocation.The fundamental theory of geoenglneering is a theory of geologlcal control,its basic theories are control theory Of geological structure,controltheory of rock mass structure,control theory of soil mass structure, and control theory ofexisting environment factor Of geologlcal they.They controll the evaluation theory andmethod of geological environment,the evaluation theory and methed of rock mass,the theory and methed of engineering geological survey and test,the theory and method Of engineering geologlcal prediction, the theory and technique of geological bedy transform,theanalysis theory and methed of stability of rockrnass and soil mass,and the guide theory ofproject and construction of geoenglneering.It may reduce blindness,increase consciousness,and may decrease 20%--30% of pecuniary loss in the geoengineering practice,by using ocr-rectly this series of geoengineering theories in the geoengineering practice.