Abstract: Poly(lactic acid) (PLA)/halloysite (HNT) composites were prepared by a blending method, and the effect of HNT content on the mechanical properties, thermal properties and microstructure of the composites were investigated. The results indicated that there was a significant reinforcement effect of HNT on PLA, and the mechanical properties of PLA/HNT composites were greatly improved. The optimum mechanical properties can be obtained when 8 wt % of HNT was incorporated into PLA. However, the addition of HNT led to a decrease in elongation at break and impact strength of the composites. The relative crystallinity and melting temperature of the composites were improved in the presence of HNT. The thermal stability of the composites was also improved significantly. Moreover, the morphological observation indicated that the fracture surface of the composite became smoother, indicating a transformation from ductile fracture to the brittle one.