  The most general SU(3)-singlet space of gauged N=8 supergravity in
four-dimensions is studied recently. The SU(3)-invariant six scalar fields are
realized by six real four-forms. A family of holographic N=1 supersymmetric RG
flows on M2-branes in three-dimensions is described. This family of flows is
driven by three independent mass parameters from the N=8 SO(8) theory and is
controlled by two IR fixed points, N=1 G_2-invariant one and N=2 SU(3) x
U(1)-invariant one. The generic flow with arbitrary mass parameters is N=1
supersymmetric and reaches to the N=2 SU(3) x U(1) fixed point where the three
masses become identical. A particular N=1 supersymmetric SU(3)-preserving RG
flow from the N=1 G_2-invariant fixed point to the N=2 SU(3) x U(1)-invariant
fixed point is also discussed.
