ABSTRACT: In practical engineering is required to provide seismic protection of a rigid body, connected with one or more elastic elements. This task falls a little aside from structural mechanics, which deals mainly with seismic protection of structures and buildings. The rigid body has six degrees of freedom. Seismic forces and moments are obtained in the direction of the six generalized coordinates, which may follow three arbitrary mutually perpendicular directions in space. The article is theoretical in nature and helps us to expand our knowledge of Seismic Mechanics.