  The statistics of dark matter halos is an essential component of
understanding the nonlinear evolution in modified gravity cosmology. Based on a
series of modified gravity N-body simulations, we investigate the halo mass
function, concentration and bias. We model the impact of modified gravity by a
single parameter \zeta, which determines the enhancement of particle
acceleration with respect to GR, given the identical mass distribution (\zeta=1
in GR). We select snapshot redshifts such that the linear matter power spectra
of different gravity models are identical, in order to isolate the impact of
gravity beyond modifying the linear growth rate. At the baseline redshift
corresponding to z_S=1.2 in the standard \Lambda CDM, for a 10% deviation from
GR(|\zeta-1|=0.1), the measured halo mass function can differ by about 5-10%,
the halo concentration by about 10-20%, while the halo bias differs
significantly less. These results demonstrate that the halo mass function
and/or the halo concentration are sensitive to the nature of gravity and may be
used to make interesting constraints along this line.
