A method of harvesting mesenchymal stem cells from human amniotic fluid uses a two-stage culture protocol comprising culturing human amniocytes and then culturing mesenchymal stem cells. For culturing human amniocytes, primary amniocyte cultures are set up using routine or standard culture protocol in a cytogenetic laboratory. Non-adherent human amniotic fluids cells in the supernatant medium are collected. For culturing mesenchymal stem cells ("MSC"), the non-adherent cells are centrifuged and then plated with an alpha-modified Minimum Essential Medium supplemented with fetal bovine serum. Incubate with humidified CO.sub.2 for MSC growth. Reverse transcription polymerase chain reaction ("RT-PCR") and immunocytochemical analyses reveal that Oct-4 mRNA and OCT-4 protein expression is detectable in the cultured amniotic fluid mesenchymal stem cells ("AFMSCs"). Under differentiation culture conditions, the AFMSCs can be induced to develop into multi-lineage cells, such as adipocytes, osteocytes, neuronal cells, etc.