On manifest SU(4) invariant superstring action in AdS(5) x S(5)
  We discuss manifestly SL(2,C)x SU(4) and kappa invariant superstring action in AdS(5) x S(5) background in the framework of Green-Schwarz formulation. The action is formulated in terms of 16 Poincare fermionic coordinates which through AdS/CFT correspondence should represent N=4 SYM superspace and 16 superconformal fermionic coordinates. The action is also manifestly invariant with respect to the usual N=4 Poincare superalgebra transformations. kappa-symmetry gauge fixing and the derivation of light-cone gauge action is simplified. 
R.R.Metsaev