  A superspace formulation of type II superstring background with manifest
T-duality symmetry is presented. This manifestly T-dual formulation is
constructed in a space spanned by two sets of nondegenerate super-Poincare
algebra. Supertorsion constraints are obtained from consistency of the
kappa-symmetric Virasoro constraints. All superconnections and vielbein fields
are solved in terms of a prepotential which is one of the vielbein components.
AdS5xS5 background is explained in this formulation.
