  The generating functional of correlation functions of the currents
corresponding to general massless $p$-form potential is calculated in $AdS/CFT$
correspondence of Maldacena. For this we construct the boundary-to-bulk Green's
functions of $p$-form potentials. The proportional constant of the
current-current correlation function, which is related to the central charge of
the operator product expansion, is shown to be $c=(d-p\over 2\pi^{d/2}) (\Gamma
(d-p) \over \Gamma ({d\over 2}-p)).$ The result agrees with the known cases
such as $p=1$ or 2.
