This thesis constructed the theory of the radical of Lie algebras.And we made use of the knowledge of the radical theory to study the structure of Lie algebras.If r is a property,and also satisfies the following condition:(Rl):Every homomorphic image V of r—lie algebra L is again an r—lie algebra;(R2):Every lie algebra L has a maximum r—ideal R(L);(R3):R(L/R(L))=0.We define the rb property of Lie algebra: L is a rb—Lie algebra if and only if every homomorphic image of L contains non-nilpotent ideal in r(E), then rb is a property.This specific work is in the following:(1)If Witt algebra is a simple Lie algebra,and its Baer-radical rb(L)=0.(2) To any ideal I of Loop algebra L(L), there exists an I1(?)F[l,l-1] which makes I=I1(?)L, L is a simple Lie algebra.(3)The Baer-radical of the twist affine lie algebras is rb(L(L))—Fc.F is a closed domain of characteristic zero algebraic.c is a central element.(4)If L(L):=L(L)+Fc can make a Lie algebra on the base of the following computation:[a+Fc, b+Fc]:=[a, b]0+ψ(a, b)c,ψ(a, b):=(da, b)0, for any a,b∈E L(L), for any ideal I of L(L), there exists I1(?)L(L) which makes I=I1+Fc. |