We present a simple form of the Type IIB string action on AdS(5) x S-5. The result is achieved by fixing kappa-symmetry in the Killing spinor gauge defined by the projector of the Killing spinor of the D3 brane. We show explicitly that in this gauge the superspace is greatly simplified which is the crucial ingredient for the simple string action. (C) 1998 Elsevier Science B.V. All rights reserved.