  Two spin-doublet states of %$3/2^+$-$1/2^+$ and $7/2^+$-$5/2^+$ in
$^7_{\Lambda}$Li are studied on the basis of the $\alpha +\Lambda +n+p$
four-body model. We employ the two-body interactions which reproduce the
observed properties of any subsystems composed of $\alpha N$, $\alpha \Lambda$
and $\alpha NN$, and $\alpha \Lambda N$. Furthermore, the $\Lambda N$
interaction is adjusted so as to reproduce the $0^+$-$1^+$ splitting of in
$^4_{\Lambda}$H. The calculated energy splittings of $3/2^+$-$1/2^+$ and
$7/2^+$-$5/2^+$ states in $^7_{\Lambda}$Li are 0.69 MeV and 0.46 MeV, which are
in good agreement with the resent observed data. The spin-dependent components
of the $\Lambda N$ interaction are discussed.
