  We apply dynamical string models of heavy-ions collisions at high energies to
the analysis of event-by-event fluctuations. Main attention is devoted to a new
variable proposed to study "equilibration" in heavy-ions collisions. Recent
results of the NA49 collaboration at CERN SPS are compared with predictions of
the Quark-Gluon String Model (QGSM), which gives a good description of
different aspects of multiparticle production for collisions of nucleons and
nuclei. It is shown that the new observable and other results of the NA49
analysis of event-by-event fluctuations are correctly reproduced in the model.
We discuss dynamical effects responsible for these fluctuations and give the
predictions for p-p, p-Pb and Pb-Pb collisions at RHIC and higher energies.
