  In this Paper we consider a problem of formation and evolution of orbital
parameters of a binary primordial black hole (PBH) due to gravitational
interaction with clustering cold dark matter (CDM). Mass and initial separation
have values, which are appropriate for the problem of explanation of the
LIGO/Virgo events by coalescing binary PBHs. We consider both radiation
dominated and CDM dominated stages of the evolution using numerical and
semi-analytical means. We show that at the end time of our numerical
simulations binary's semimajor axis decreases by approximately one hundred
times, while its angular momentum decreases by ten times, in comparison to the
standard values, which do not take into account effects associated with CDM
clustering. We check that our conclusions are hardly affected by numerical
artefacts. We estimate the merger rate of binary PBHs due to emission of
gravitational wave at the present time both in the standard case when the
effects associated with clustering are neglected and in the case when they are
taken into account and show, that these effects could increase the merger rate
at least by $6-8$ times in comparison to the standard estimate. This, in turn,
means, that a mass fraction of PBHs, $f$, should be smaller than it was assumed
before.
