ξ-submanifold in the Euclidean space R m+p is a natural extension of the concept of selfshrinker to the mean curvature flow in R m+p . It is also a generalization of the λ-hypersurface defined by Q.-M. Cheng et al to arbitrary codimensions. In this paper, some characterizations for ξ-submanifolds are established. First, it is shown that a submanifold in R m+p is a ξ-submanifold if and only if its modified mean curvature is parallel when viewed as a submanifold in the Gaussian space (R m+p , e − |x| 2 m ·, · ); Then, two weighted volume functionals V ξ andV ξ are introduced and it is proved that ξ-submanifolds can be characterized as the critical points of these two functionals; Also, the corresponding second variation formulas are computed and the (W -)stability properties for ξ-submanifolds are systematically studied. In particular, it is proved that m-planes are the only properly immersed, complete W -stable ξ-submanifolds with flat normal bundle under a technical condition. It would be interesting if this additional restriction could be removed.2000 Mathematics Subject Classification. Primary 53A30; Secondary 53B25.