The RENO experiment has successfully measured $\theta_{13}$ using the disappearance of electron anti-neutrinos in three-flavor neutrino oscillations. We search for sterile neutrinos in four-flavor oscillation model using roughly 1500 days of data collected by the RENO experiment. We have not seen any positive signal and obtain an excluded region of the oscillation parameters. We present an excluded contour plot in $sin^{2}2\theta_{14}-\Delta m^{2}_{41}$ space.