Two-phase flows with particles appear widely in nature and industrial applications. Thus it is very important to research the characteristics of particle-laden flows. In this paper, a series numerical simulation of a particle-laden channel flow was carried out to investigate the effects of particle parameters. The interaction between the continuous phase and particles was calculated by the two-way Euler-Lagrange coupled method. The Stokes number was found to be the characteristic parameter to indicate the distribution of the particle. The particle's preferential concentration in the low-speed and low-vorticity zones was verified. The turbulence suppression occurred in these simulations and the turbulence modulation by particles was found to have an approximate linear correlation with the average mass loading. However, the particle diameter and the particle density ratio was also found to influence the turbulence modulation.