  Numerical simulations play an important role in current astronomy researches.
Previous dark-matter-only simulations have represented the large-scale
structure of the Universe. However, nowadays, hydro-dynamical simulations with
baryonic models, which can directly present realistic galaxies, may twist these
results from dark-matter-only simulations. In this chapter, we mainly focus on
these three statistical methods: power spectrum, two-point correlation function
and halo mass function, which are normally used to characterize the large-scale
structure of the Universe. We review how these baryon processes influence the
cosmology structures from very large scale to quasi-linear and non-linear
scales by comparing dark-matter-only simulations with their hydro-dynamical
counterparts. At last, we make a brief discussion on the impacts coming from
different baryon models and simulation codes.
