  We investigate space-time supersymmetry of the model of multiple M2-branes
proposed by Bagger-Lambert and Gustavsson. When there is a central element in
Lie 3-algebra, the model possesses an extra symmetry shifting the fermions in
the central element. Together with the original worldvolume supersymmetry
transformation, we construct major part of the eleven dimensional space-time
super-Poincar\'{e} algebra with central extensions. Implications to transverse
five-branes in the matrix model for M-theory are also discussed.
