Abstract: Blend films of poly(L-lactic acid) (PLLA) and ethylcellulose (EC) with various compositions were prepared by casting from respective chloroform solution. The obtained blends were characterized with FT-IR, DSC, and X-ray diffraction. All results showed that PLLA and EC were liable to form interpolymer hydrogen bonds, and PLLA and EC were partially miscible. The crystal formation and crystal perfection of PLLA-EC blend relied on PLLA/EC ratios, which resulted from interpolymer hydrogen bonds of PLLA with EC. The degradation of blend in phosphoric buffer was great affected by PLLA-EC ratios. The degradation of PLLA-EC blend increased greatly with the ethylcellulose contents as PLLAEC being less than 70/30. Thus PLLA-EC blends with various properties may be used as biodegradable polymers.