In this paper, the mechanical properties of starch/polylactic acid-based composites were studied. Starch / polylactic acid blends were prepared by solution, using dichloromethane and ethanol as a solvent for polylactic acid and starch, respectively. Glycerol was used as a starch modifier to improve the compatibility between polylactic acid and starch. The result of this study shows existence of Glycerol in the blend can significantly affect the tensile properties of the blend. Increase in the length to the rupture, was maximum when a combination of 90% polylactic acid and 10% modified starch were used in the mixture.