The growth process of microcrystalline silicon thin films deposited at high growth rate was monitored online by optical emission spectroscopy. The properties of the material were studied by Raman and FTIR spectroscopy. The results indicated that the I［SiH*］/I［Hβ*］ ratio decreased during the process, particularly at low total gas flows, which was consistent with the Raman results. The I［Hβ*］/I［Hα*］ratio detected after the plasma glowed for 5 minutes showed that the electronic temperature first decreased then increased with the increasing Ftotal. The FTIR spectra showed that the microstructure defect fraction R first decreased then increased with increasing Ftotal. This means that the electronic temperature in hydrogen plasma plays an important role in determining the properties of the microcrystalline silicon thin films.