  We consider integrability properties of the superstring on $AdS_{5}\times
S^{5}$ background and construct a new one parameter family of currents which
satisfies the vanishing curvature condition. We present the Hamiltonian
analysis for the sigma model action and determine the Poisson algebra of the
transition matrices. We reveal the generalization of the $\mathbb{Z}_{4}$
automorphism analogous to the sigma models defined on a symmetric space coset.
A possible regularization scheme for the ambiguities present, which respects
the generalized automorphism, is also discussed.
