Abstract: To enhance the compatibility between halloysite nanotubes(HNTs) and poly(propylene carbonate)(PPC), HNTs were surface-modified by a silane coupling agent(KH-560). PPC/HNTs nanocomposites were prepared by melt blending and then characterized by Fourier-transform infrared spectroscopy, rheometer and thermogravimetric analysis. The results indicated that KH-560 was successfully grafted onto HNTs with a grafting rate of 26 wt %. HNTs achieved good dispersion in the PPC matrix due to the surface modification. The thermal degradation of PPC was suppressed in the presence of of surface-modified HNTs, indicating that its thermal stability was enhanced by HNTs. Moreover, the tensile strength of PPC was also significantly improved with the addition of surface-modified HNTs.