Abstract: Polylactide/talc composites were prepared through in situ polymerization using silane coupling agent modified talcum powder（Talc）, which was characterized using Fourier transform infrared spectroscopy (FTIR)，scanning electronic microscope (SEM)，nuclear magnetic resonance (NMR)，thermo gravimetric (TG)，and polarizing optical microscope (POM). It showed that talc particles were dispersed uniformly in the matrix.The tensile and impact strengths of the PLA/Talc composites with 3 % talc were improved by 102.56 % and 47.83 %, respectively，compared with pure PLA. The thermal stability of the composites was improved visibly. Talc accelerates crystallization of PLA. Meanwhile, the degradation rate of composites was markedly accelerated.

Key words: talc, inorganicly modified, PLA, composites, in situ polymerization, mechanical properties