The ac and dc equivalent circuit models of small molecule-based bilayer organic light emitting diodes are discussed. In order to model the devices under ac bias application, the frequency-dependent properties of bilayer organic light emitting diodes have been studied using admittance spectroscopy. The equivalent circuit models of bilayer diodes, for which the interface properties between the organic layers are included, are suggested. The de model of the organic light emitting diodes is also presented, and will be compared with the experimental current-voltage characteristics. The simulated results of these equivalent circuit models are in good agreement with the measured results and these models can be used for the ac and dc modeling of small molecule-based organic light emitting diodes.