A.R. Its, A.G. Izergin, V.E. Korepin, N.A. Slavnov Temperature Correlations of Quantum Spins (13K, LATeX) ABSTRACT. We consider isotropic XY model in the transverse magnetic field in one dimension. One can alternatively call this model Heisenberg XXO antiferromagnet. We solve the problem of evaluation of asymptotics of temperature correlations and explain the physical meaning of our result. To do this we represent quantum correlation function as a tau function of a completely integrable differential equation. This is the well-known Ablowitz-Ladik lattice nonlinear Schrodinger differential equation.