Abstract: Abstract Based on the experience gained by the author in 50 years of engineering geological activities and the present situation of engineering geological work in the country,this paper is attempting to explore the core value of engineering geology. As originated from geosciences,engineering geology has its depth of knowledge of geology. However,the integration of geological and engineering sciences enables the engineering geology to have the capability of interpretation of geological structure and phenomenon on its engineering meanings,and to create the identifi-canon of engineering geology as a branch of modern sciences. Through the engineering geological observation,judg-ment,evaluation,prediction and decision making,the core value of engineering geology can be realized. In the en-gineering geological work the theory and methodology of geology and the identification of engineering geology should be implemented and be promoted,but the advanced theoretical and technology of relevant sciences should be ap-plied to achieve new advancement of engineering geology in serving the reconstruction of the country.