///This paper introduces the principles of engineering geological dynamics of rockmass (EGDR). It points out that the mission of EGDR is to reveal the law of interaction between rockmass and geodynamic factors. The basic viewpoints of EGDR includes the following subjects: 1) the geo-dynamic genesis which means rockmass and its geological features are the results of crustal dynamic process; 2) dynamic interaction that means the engineering behavior of rockmass is the reflection of the interplay between rockmass and the geoenvironment; and 3) the point of process adjustment that infers the basic approach for engineering geohazard prevention is to adjust the interacting process between rockmass and the geodynamical environment. The following aspects have been described in details under the framework of geodynamics: 1) the dynamic genesis and geological features of rockmass; 2) the features of geo-dynamical environment of rockmass; 3) the fundamental mechanical behavir of rockmass; 4) the features and behaviours of rockmass under high crustalstress; 5) the dynamic reaction of rockmass; and 6) the reaction of ground water in rockmass.