Attempts have been made to improve the impact resistance of biodegradable thermoplastic polymer, PLA. A ductile biodegradable polymer, PCL, has been used to improve such property of PLA by using blending technique. Details of the impact fracture properties and mechanisms of PLA/PCL blends, however, have not fully been understood yet. Recently, it was also found that LTI can improve the immiscibility between PLA and PCL. In this study, PLA/PCL and PLA/PCL/LTI blends were prepared, and their impact fracture toughness values were measuredto assess the effect of PCL content and LTI addition on the impact resistance. Fracture mechanisms of the polymer blends were also characterized by scanning electron microscopy.