The natural fiber / polylactic acid (PLLA) composites were prepared with Alfa-Alfa fibers as reinforcement and PLLA as matrix. The composite materials were obtained through the simple mechanical compounding of PLLA matrix with various fibers contents up to 40 wt %, followed by drying, kneading and hot pressing into sheets and were characterized by TGA, DSC, FTIR spectroscopy, SEM and water uptake. Composites prepared from several percentages of PLLA and Alfa-Alfa fibers represent a new category of environmentally safe materials for applications to explore to reduce the raw materials cost of PLLA due to Alfa-Alfa fibers is an abundance local plant in Algeria, the increasing utilization of renewable resources will be one of the strong drivers for sustainable products.