A series of microcrystalline silicon thin films were fabricated by very high frequency plasma enhanced chemical vapor deposition (VHF-PECVD) in a single-chamber under different boron-contamination conditions. The influence of boron on the properties of intrinsic microcrystalline silicon thin film was studied. The results show that the dark conductivity decreases with the increase of boron contamination and the photosensitivity shows the opposite change. The activation energy varies due to different degrees of boron contamination on these thin films. The boron contamination decreases the crystalline volume fraction and weakens the (220) prefered orientation intensity. However, the effect of contamination is less serious to the material, prepared at relatively high power and high hydrogen dilution, which has higher crystalline volume fraction and stronger (220) preferred orientation.