Lawrence Berkeley National Laboratory

In 2010, the Relativistic Heavy Ion Collider (RHIC) launched a multistep experimental program to investigate the QCD Phase Diagram in general, and to search for the QCD Critical Point (CP) and/or 1st order phase transition in particular. The BES (Beam Energy Scan) program involves an "energy scan" of Au+Au collisions from the top RHIC energy (ρs = 200 GeV) down to energies as low as 5 GeV in NN center of mass. During the first BES run (2010), data were collected at 7.7, 11.5 and 39 GeV. It was complemented in 2011 by two other data sets at 27 and 19.6 GeV. The preparations for the remaining data taking at ps = 5 GeV are in progress. The overview of the BES program and the first experimental results are presented and discussed.