In this study, epoxidized palm oil (EPO) was utilized as a plasticizer for polylactic acid (PLA) using chloroform as a solvent by solution casting process at six weight ratios of PLA/EPO, 95/05, 90/10, 80/20, 70/30, 60/40, and 50/50, respectively. Fourier-transform infrared (FTIR) spectroscopy was used to identify the functional groups of PLA, EPO, and PLA/EPO blends. Thermal stability, mechanical, and morphological properties of the blends were investigated by thermogravimetric analyzer (TGA), tensile properties measurements, and scanning electron microscope (SEM) technique, respectively. The FTIR spectra indicate that there are some molecular interactions by intramolecular hydrogen bond between PLA and EPO. All sets of PLA/EPO blends show high thermal stability and significant improvement of mechanical properties compare to pure PLA. The highest elongation at break (about 210%) was obtained when the ratio of PLA/EPO blend was 80/20. Morphological results of PLA/EPO blends show that ESO was good miscible with PLA.