  We construct holographic Janus solutions, which describe a conformal
interface in the theory of M2-branes, in four-dimensional gauged supergravities
using a perturbative method. In particular, we study three Einstein-scalar
systems and their BPS equations, which are derived by Bobev, Pilch, and Warner
(2014). The actions of our interest are all consistent truncations of $D=11$
supergravity chosen to be invariant under $SO(4)\times SO(4)$, $SU(3)\times
U(1)\times U(1)$, and $G_2$ symmetry subgroups of $SO(8)$ respectively. The
utility of our semi-analytic result is illustrated by the calculation of
minimal area surface and the associated holographic entanglement entropy.
