  This contribution briefly reviews the reverberation mapping technique which
leads to determination of black hole masses. I focus on the emerging relation
between the broad-line region size and the active galactic nucleus (AGN)
luminosity, and on an overview of recent results of reverberation mapping
studies which are starting to cover the full AGN luminosity range. Preliminary
results and time lag determination from a reverberation mapping program of
high-luminosity quasars are also presented.
