Polarized blue electroluminescence has been achieved from the oriented poly (9, 9-dioctylfluorene) (PFO) film on a rubbed hole injection layer poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) at the CIE coordinates of (0.20, 0.21). Polarized absorption and photoluminescence spectra reveal that the dichroism of the PFO film is influenced by the rubbing strength of the alignment layer, the annealing temperature, and annealing time, among which the annealing temperature is the most significant factor. An electroluminescence polarization ratio of about 3 is achieved when the rubbing depth is 50μm, the annealing temperature is 200℃ and the annealing time is 30 min.