The purpose of this study is to synthesize nanometer calcium carbonate/poly(L-lactide) composites and evaluate its biocompatibility, and mechanical properties. The nanometer calcium carbonate/poly(L-lactide) composites was prepared by the method of solution mixing and cell culture. Its properties were analyzed using, mechanical tests, MTT assay, transmission electron microscope and scanning electron microscope. It was found that the new kind copolymer had good biocompatibility, nanometer calcium carbonate could enhance the strength of the pure poly (L-lactide) matrix. The nanometer calcium carbonate/poly (L-lactide) composites is a promising bioabsorbable material. It is worth further medical research.