Poly-L-Lactide (PLLA) composites were prepared with nano silver particles with the weight ratios of nano silver particles to PLLA (Ag/PLLA) at 0.5%, 2.5%, 5%, 7.5% and 10% (w/w). In vitro cytotoxicity tests were conducted firstly to evaluate the cytotoxicity of the composites. The results indicated that PLLA, 0.5%, 2.5% and 5% Ag/PLLA composites were nontoxic to cells, while 7.5% and 10% Ag/PLLA composites were significantly toxic to cells. Cell proliferation experiments and antibacterial tests were also performed. 5% Ag/PLLA was found the best for cell proliferation with obvious antibacterial property. Thus, Ag/PLLA can be used as nontoxic scaffolds for tissue engineering with antibacterial property.