In this paper, a one-dimensional self-consistent fluid model is applied to simulate high frequency atmospheric pressure glow discharges. The results show that the plasma density and current density depend strongly on the excitation frequency. When the excitation frequency is below 13.56 MHz, the discharge operates in the a mode, and when the excitation frequency is above 13.56 MHz, the discharge operates in a gamma-like mode. The densities of species including SiH3+, SiH3-,SiH3, SiH2, H, Ar+ Ar* and electron are enhanced with the frequency increasing from 6.78 to 27.12 MHz. Similar discharge mode transition was observed experimentally in radio frequency atmospheric pressure He glow discharges. The effects of excitation frequency on plasma characteristics and densities of precursors for pc-Si:H film are further discussed. This study reveals that an appropriate excitation frequency is important for the growth of pc-Si:H film. (C) 2011 Elsevier B.V. All rights reserved.