In this study, we prepared composite film by depositing Langmur-Blodgett (LB) film containing Bacteriorhodopsin (bR) on ITO coated with polypyrrole (PPy). We studied its photoelectric properties and the influence of PPy film on the photoelectric properties of LB films containing bR at different pH. The results showed that PPy film with a certain thickness could increase the photocurrent of bR LB film 30-50% in comparison with that of bR LB film at pH 8.3.