Poly(lactic acid) (PLA), one of the most commonly used synthetic biodegradable polymers having good mechanical properties, is blended with soluble eggshell membrane protein (SEP) by solution casting from hexafluoroisopropanol to improve the mechanical properties of SEP. When PLA/SEP proportion is 9 : 1, the cast film has much better mechanical properties than neat SEP film and significantly improved biocompatibility compared to neat PLA film, as demonstrated by tensile tests and cell culture of NIH3T3. The PLA/SEP blend films were further characterized by field emission gun scanning electron microscopy, attenuated total reflectance Fourier transform infrared spectroscopy, differential scanning calorimetry, X-ray diffraction, and contact angle measurements. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117:1955-1959,2010