The effect of ultrasound irradiation on the blend of poly(lactic acid)(PLA) and poly(1,4-cyclohexylen dimethylene 1,4-cyclohexane dicarboxylate)(PCCD) was investigated. The blends of PLA/PCCD(50/50) (PCCD50) were prepared by a melt mixer attached with an ultrasonic device and their properties were analyzed. The properties of sonicated blends were found to be significantly dependent on the duration of the ultrasound irradiation. Surprisingly, for PCCD50, 1 min sonicated samples showed the impact strength over three times higher than untreated ones. The improvement was thought to be due to better adhesion between PLA and PCCD phases.