  An extended version of the antisymmetrized molecular dynamics to study
structure of $p$-$sd$ shell hypernuclei is developed. By using an effective
$\Lambda N$ interaction, we investigate energy curves of $^9_\Lambda$Be,
$^{13}_\Lambda$C and $^{20,21}_\Lambda$Ne as function of nuclear quadrupole
deformation. Change of nuclear deformation caused by $\Lambda$ particle is
discussed. It is found that the $\Lambda$ in p-wave enhances nuclear
deformation, while that in s-wave reduces it. This effect is most prominent in
$^{13}_\Lambda$C. The possibility of the parity inversion in $^{20}_\Lambda$Ne
is also examined.
