S53P4 bioactive glass nanoparticles (BGn) were prepared by the melting-quenching method at 1400 degrees C followed by ball milling. The prepared glass nanoparticles were used for surface decoration of poly-L-lactic acid (PLLA) nanofibers fabricated by electrospinning method. The microstructure, morphology and chemical functional groups of the nanomaterials were characterized by XRD, FESEM, and FTIR techniques. The results confirmed the successful synthesis of amorphous glass nanoparticles with the diameter ranged from similar to 100 to 800 nm and PLLA nanofibers with an average diameter of 500 nm. PLLA/BGn nanocomposites showed a uniform distribution of the BGn on the surface of PLLA nanofibers. The growth, viability, and proliferation of the cultured human bone marrow mesenchymal stem cells (hMSCs) on the prepared nanomaterials were examined using various biological assays, including MTT cytotoxicity, ALP activity, calcium biomineralization, Alizarin red staining, and gene expression. The biological results clearly showed that the growth, proliferation and osteogenic ability of hMSCs were significantly improved due to the surface modification of PLLA nanofibers with BGn. It was concluded that the 3D structure, optimum porosity and balanced dissolution rate of PLLA/BGn nanocomposites led to the promoted cellular activity.