  The bottom-up approach of the AdS/CFT correspondence leads to the study of
field equations in an $AdS_5$ background and from their solutions to the
determination of the hadronic mass spectrum. We extend the study to the
equations of $AdS_5$ gravitons and determine from them the glueball spectrum.
We propose an original presentation of the results which facilitates the
comparison of the various models with the spectrum obtained by lattice QCD.
This comparison allows to draw some phenomenological conclusions.
