The present study introduced a novel biocompatible electrospun membrane composed of poly (l-lactic acid) (PLLA) and water-insoluble keratin precipitates from wool hydrolyzed solution. Ultrafine nanofibrous membranes were successfully prepared by electrospinning the blend of PLLA and keratin/alcohol suspension. Uniform structure of the composite nanofibers was observed by scanning electron microscopy. Transmission electron microscopy pictures indicated keratin was evenly distributed within the composite fibers. The result of Fourier transform infrared (FT-IR) spectra revealed the composition of the keratin/PLLA membrane. X-ray differential spectroscopy suggested that higher crystallinity can be observed from keratin/PLLA composite nanofibers than pristine keratin precipitates. The thermogravimetric analyzer spectra indicated that keratin/PLLA composite fibers possessed more constant thermostability than pristine keratin precipitates. The invitro degradation of keratin/PLLA composite nanofibers was evaluated by FT-IR spectra and ultraviolet spectra. The experimental results showed that the degradation rate was fast on the first day and slow in the following period. The biocompatibility of the keratin/PLLA composite membrane was examined by MTT assay and the cell proliferation profile was observed by fluorescent micrographs. The results indicated that with the promoting effect on cell adherence and proliferation, this composite material was suitable as a biomedical fabrics candidate for use in drug delivery vehicle and tissue engineering scaffolds.