Various groups have presented findings that human mesenchymal stem cells (MSCs) have both immunomodulatory and trophic properties. MSCs tend to act indirectly at sites of injury or damage through the secretion of paracrine factors in vitro & in vivo. For example, our studies have been done using a transgenic Alzheimer’s disease mouse model where intraparenchymal injections of MSCs resulted in the reduction of amyloid plaque levels, anti-apoptosis, activation of endogenous neural stem cell and also activate proteasome in neuron. In addition, efficient MSC delivery also is significant issue for human study. By possessing a broad range of functions, MSCs hold great potential in being used as a novel treatment for various diseases including neurodegenerative disorders.