Environment-friendly or "green" composites (GCs) made from micro-fibril bamboo fiber (BF) and biodegradable poly-lactic acid (PLA) resin were fabricated using a hot-pressing methods. The effect of BF content on the flexural properties and impact energy of the GCs was investigated. The results show that the flexural properties and impact energy of the GC samples are tremendously affected by the addition of BF. Both the flexural properties and impact energy increase with increasing the BF content up to 40% and then decrease with BF contents less or more than 40% by mass. This was because of the existence of internal defects such as voids was observed for the GC samples reinforced with less or more than 40% mass of BF.