Abstract: The properties of upcenter series of 3-Lie algebras were studied. The relations between the class of nilpotent 3-Lie algebras and the dimensions of ideals with the upcenter series were privied. It is proved that the upcenter series are privied. It is proved that the upcenter series of every maximal subalgebra is completely determined by that of the nilpotent 3-Lie algebras.

Key words: 3-Lie algebra, coclass, nilpotency