  The Daya Bay Reactor Neutrino Experiment has measured a non-zero value of the
neutrino mixing angle $\theta_{13}$ with a significance of 7.7 standard
deviations by a rate-only a nalysis. The distortion of neutrino energy spectrum
carries additional oscillation information and can improve the sensitivity of
$\theta_{13}$ as well as measure neutrino mass splitting $\Delta m^{2}$ . A
rate plus shape analysis is performed and the results have been released in
August at NuFact 2013.
  Detector energy non-linearity response study is crucial for the rate plus
shape analysis. In this contribution, We present A brief description of energy
non-linearity study at Daya Bay.
