  We study properties of high energy factorisable gluon densities focusing on
saturation effects. In particular we show that the property of saturation of
unintegrated gluon density allows for introduction of thermodynamical entropy
associated with production of gluons. This is due to the observation that
saturation scale acts like a mass of a gluon which related with temperature via
thermodynamical relations allows for calculations of entropy. We also show that
obtained entropy behaves like multiplicity of produced gluons.
