Abstract: The T-derivations of 3-Lie algebras,T-derivation Lie algebra TDer(L),and its structure were studied.The relations between TDer(L)and Der(L),ad(L)were discussed.It is proved that the inner derivation algebra ad(L)is an ideal of TDer(L).If L is a perfect 3-Lie algebra over a field F with Char F≠5,centralizers of derivation algebra and inner derivation algebra in TDer(L)are both zero.

Key words: 3- Lie algebra, T-derivation, derivation, inner derivation