  We show how correlation functions of the spin-1/2 Heisenberg chain without
magnetic field in the anti-ferromagnetic ground state can be explicitly
calculated using information contained in the quantum Knizhnik-Zamolodchikov
equation [qKZ]. We find several fundamental relations which the inhomogeneous
correlations should fulfill. On the other hand, it turns out that these
relations can fix the form of the correlations uniquely. Actually, applying
this idea, we have obtained all the correlation functions on five sites.
Particularly by taking the homogeneous limit, we have got the analytic form of
the fourth-neighbor pair correlator < S_j^z S_{j+4}^z >.
