  The analytical expression for dynamical charge susceptibility in layered
cuprates has been derived in the frame of singlet-correlated band model beyond
random-phase-approximation (RPA) scheme. Our calculations performed near
optimal doping regime show that there is a peak in real part of the charge
susceptibility $\chi({\bf q},\omega)$ at {\bf Q} = ($\pi$, $\pi$) at strong
enough inter-site Coulomb repulsion. Together with the strong maximum in the Im
$\chi({\bf Q},\omega)$ at 15 meV it confirms the formation of low-energetic
plasmons or charge fluctuations. This provides a jsutification that these
excitations are important and together with a spin flcutuations can contribute
to the Cooper pairing in layered cuprates. Analysing the charge susceptibilitiy
with respect to an instability we obtain a new plasmon branch, $\omega_{\bf
q}$, along the Brillouin Zone. In particular, we have found that it goes to
zero near {\bf Q}$_{CDW} \approx (2\pi/3, 2\pi/3)$.
