The present invention relates to monoclonal antibodies specifically binding to a membrane antigen of human mesenchymal stem cells, hybridoma cell lines producing the same, and methods for identifying or isolating human mesenchymal stem cells using the same. The monoclonal antibodies of this invention exhibit excellent specificity to human mesenchymal stem cells, inter alia, bone marrow-derived human mesenchymal stem cells, so that it allows for the identification and isolation of human mesenchymal stem cells with much higher specificity.