  Using a hadron and string cascade model, JPCIAE, we investigated the
dependence of event-by-event charge fluctuation on the energy, centrality,
window size, resonance decay, and the final state interaction for $Pb+Pb$
collisions at SPS and LHC energies and $Au+Au$ collisions at RHIC energies. The
JPCIAE results of charge fluctuation as a function of the rapidity window size
in $Pb+Pb$ collisions at SPS energies were compared with the preliminary NA49
data. Comparisons with STAR and PHENIX data of $Au+Au$ collisions at
$\sqrt{s_{nn}}$=130 GeV were also given. It seems that the final state
interaction and resonance decay play a gentle role on the charge fluctuations.
The charge fluctuations are slightly decreasing with or nearly independent of
the reaction energy and hardly depend on the collision centrality.
