  The Reactor Experiment for Neutrino Oscillation (RENO) has been taking
electron antineutrino ($\overline{\nu}_{e}$) data from the reactors in
Yonggwang, Korea, using two identical detectors since August 2011. Using
roughly 500 live days of data through January 2013 we observe 290,775 (31,514)
reactor $\overline{\nu}_{e}$ candidate events with 2.8 (4.9)% background in the
near (far) detector. The observed visible positron spectra from the reactor
$\overline{\nu}_{e}$ events in both detectors show discrepancy around 5 MeV
with regard to the prediction from the current reactor $\overline{\nu}_{e}$
model. Based on a far-to-near ratio measurement using the spectral and rate
information we have obtained $\sin^2 2 \theta_{13} = 0.082 \pm 0.009({\rm
stat.}) \pm 0.006({\rm syst.})$ and $|\Delta m_{ee}^2|
=[2.62_{-0.23}^{+0.21}({\rm stat.})_{-0.13}^{+0.12}({\rm syst.})]\times
10^{-3}$eV$^2$.
