  We discuss the NSR formulation of the superstring action on AdS_5 X S^5
proposed recently by Kallosh and Tseytlin in the Green-Schwarz formalism.We
show that the stress-energy tensor corresponding to the NSR action for AdS
superstring contains the branelike terms, corresponding to exotic massless
vertex operators (refered to as the branelike vertices). The corresponding
sigma-model action has the manifest SO(1,3) X SO(6) invariance of superstring
theory on AdS_5 X S^5. We argue that adding the branelike terms is equivalent
to curving the space-time to obtain the AdS_5 X S^5 background. We commence the
study of the proposed NSR sigma-model by analyzing the scattering amplitudes
involving the branelike vertex operators.The analysis shows quite an unusual
momentum dependence of these scattering amplitudes.
