PrBaCo₂O_{5+ δ} double-perovskite has been identified as promising cathode for intermediate temperature SOFC. Research has shown that oxygen diffusivity and surface defects sites that promote the surface reactivity can be greatly enhanced due to the ordered structure and non-stoichiometry of such material.  However, there have been very few detailed investigations on the ORR mechanisms and kinetics of PrBaCo₂O_{5+ δ}, including identifying the rate-limiting steps. In this work, oxygen reduction reaction mechanisms of PrBaCo₂O_{5+ δ} cathode were studied. The ORR kinetics was evaluated through EIS toward the PrBaCo₂O_{5+ δ} /GDC/ PrBaCo₂O_{5+ δ} symmetric cell configuration. The complex nonlinear least square (CNLS) fitting results shows that oxygen reduction on porous PrBaCo₂O_{5+ δ} electrode is limited by surface chemical exchange and solid state diffusion not the traditionally TPB charge transfer process under the limit of semi-infinite electrode. According to the reaction order under different temperature and Po₂, oxygen surface incorporation is supposed to be the main rate-limiting step for the overall reaction rate with the certain microstructure.