This trial aims to investigate the effect of donated umbilical cord blood stem cells in the treatment of Rheumatoid Arthritis. The trial is being conducted by the 323 Hospital of Chinese People's Liberation Army Xi'an in Shaanxi in conjunction with Alliancells Bioscience Corporation Ltd. The study proposes to recruit 150 patients with confirmed rheumatoid arthritis between July 2012 and December 2013. The participants will receive a single intravenous injection of donated umbilical cord cells. Participants will be assessed for complications and for changes in their immune profile and other activity and pain measures over a six month period.