  A manifestation of a novel type of hysteresis related to the parametric
resonance in the system of coupled Josephson junctions is demonstrated.
Opposite to McCumber and Steward hysteresis, we find that the width of this
hysteresis is inversely proportional to the McCumber parameter and depends also
on coupling between junctions and the boundary conditions. An investigation of
time dependence of the electric charge in superconducting layers allow us to
explain the origin of this hysteresis by different charge dynamics for
increasing and decreasing bias current processes. The effect of wavelength of
the longitudinal plasma waves created at the resonance on the charging of
superconducting layers is demonstrated. We found a strong effect of the
dissipation in the system on the amplitude of the charge oscillations at the
resonance.
