Biodegradable and biocompatible materials are the basis for medical application. As an initial step for developing bone internal fixation materials, the biological evaluation of poly-l-lactic acid/bioactive glass (PLLA/BG) composite in vitro and in vivo, including the hemolysis test, pyrogen test, acute systemic toxicity test, genetic toxicity test, anaphylaxis test, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) test, direct cell culture and in vivo implant experiment, was performed. The results indicated that PLLA/BG composite showed no acute systemic toxicity, genetic toxicity, anaphylaxis reaction, and pyrogen reaction, and the hemolysis ratio was 0.39%. MTT assay indicated that no cytotoxic effect was observed for the PLLA/BG composite, and in addition, a significant increase in cellular activity compared to the negative control group was found. Excellent adhesion between fibroblast and PLLA/BG material was observed, the fibroblasts cultured on the PLLA/BG composite substrates revealed a higher proliferation and differentiation rate than those on the pure PLLA substrates. In vivo implant experiment showed that the PLLA/BG composite could maintain the mechanical properties during the course of fracture therapy, and the malleolar fracture of rabbits was healed in 8 weeks on the whole. Therefore, PLLA/BG composites have a promising biological response as a potential implant material.