Let L be an n-dimensional non-abelian nilpotent Lie algebra andwhere M(L) is the Schur multiplier of a Lie algebra L. The structures of nilpotent Lie algebras L when s(L) ∈ {0, 1, 2, 3, 4, 5} are determined. In this paper, we classify all non-abelian nilpotent Lie algebras L when s(L) = 6, 7.