Poly(lactic acid)-graft-maleic anhydride (PLA-g-MAH) prepared by melt blending was used to compatiblize poly(lactic acid)/poly(butylene adipate-co-butylene terephthalate) (PLA/PBAT) blends. The structure and properties of PLA/PBAT/PLA-g-MAH composites were investigated by fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), universal testing machine, pendulum impact tester, differential scanning calorimeter (DSC) and the hydrolysis of alkaline solution. SEM results showed that the phase interface became blurry between PLA and PBAT in PLA/PBAT blends with compatibilizer PLA-g-MAH, indicated that the PLA-g-MAH had certain compatibilized effect on PLA/PBAT blends. The incorporation of PLA-g-MAH resulted in a slight decrease of tensile strength and flexural strength compared with pure PLA, but improved impact strength and elongation at break about 17 times compared with pure PLA with added PLA-g-MAH. Moreover, the adding of PLA-g-MAH improved the biodegradability of PLA/PBAT blend.