  The medium baseline reactor antineutrino experiment, Jiangmen Underground
Neutrino Observatory (JUNO), which is being planed to be built at Jiangmen in
South China, can determine the neutrino mass hierarchy and improve the
precision of three oscillation parameters by one order of magnitude. The
sensitivity potential on these measurements is reviewed and design concepts of
the central detector are illustrated. Finally, we emphasize on the technical
challenges we meet and the corresponding R&D efforts.
