In this paper, high quality orthorhombic boron nitride （o-BN） films were prepared on Si（100） substrate by plasma-enhanced pulsed laser deposition （PE-PLD） for the first time. The films were characterized by Fourier transform infrared （FTIR） spectroscopy，glancing-angle X-ray diffraction （XRD） and atomic force microscopic （AFM）. In the FTIR spectrum of the film, we can see three characteristic peaks around 1189cm-1, 1585cm-1 and 1450cm-1 of o-BN. The diffraction peaks ［111］, ［020］, ［021］, ［310］ and ［243］ all appeared in XRD, especially ［243］ and ［310］ crystal plane diffraction were very strong. The surface morphology was closely observed by AFM photograph.