  We study the evolution of correlation function of dark matter halos in the
CDM class of models. We show that the halo correlation function does not evolve
in proportion with the correlation function of the underlying mass
distribution. Earliest halos to collapse, which correspond to rare peaks in the
density field, cluster very strongly. The amplitude of halo correlation
function decreases from its initial, large, value. This decrease continues till
the average peaks have collapsed, after which, the amplitude grows at a slow
rate. This behaviour is shown to be generic and the epoch of minimum amplitude
depends only on the rms fluctuations in mass at the relevant scale and, to a
much smaller extent, on the slope of the power spectrum at that scale. We
discuss the relevance of this result for interpretation of observations of
galaxy and quasar clustering.
