  We call a subalgebra $U$ of a Lie algebra $L$ a $CAP$-subalgebra of $L$ if
for any chief factor $H/K$ of $L$, we have $H \cap U = K \cap U$ or $H+U =
K+U$. In this paper we investigate some properties of such subalgebras and
obtain some characterizations for a finite-dimensional Lie algebra $L$ to be
solvable under the assumption that some of its maximal subalgebras or
$2$-maximal subalgebras be $CAP$-subalgebras.
