Numerical analysis in combination with the experimental data for
Cr

:ZnSe as well as Ti:sapphire lasers reveal the following
main mechanisms of the multiple pulse generation for the Kerr-lens
mode-locked solid-state lasers: (i) continuum amplification due to
the spectral loss growth for the ultrashort or chirped pulse and
(ii) bounded perturbation rise for the high-energy pulse. The role
of such laser parameters as gain saturation and relaxation,
saturable and unsaturable loss, self-phase modulation,
Kerr-lensing, and pump intensity is analyzed. This analysis
provides basic directions of the single pulse stability
enhancement and of the multiple pulse generation control.