Blend films of poly(L-lactic acid) (PLLA) and cellulose with various composition was prepared by casting from trifluoroacetic acid solution. One hydroxyl group per each glucose unit was esterified by trifluoroacetic acid. The trifluoroacetyl group was hydrolyzed completely during the degradation, Weight losses for 90/10 and 75/25 PLLA/cellulose blends by proteinaze K were greatly increased compared with pure PLLA sample due to the large depression of the crystallinity of PLLA component, while cellulase was effective only for the degradation of pure cellulose film.