The T2K experiment is a long baseline neutrino oscillation experiment that uses the intense muon neutrino beam produced at J-PARC (Tokai, Japan) and Super-Kamiokande detector at 295 km away as the far detector to measure the mixing angle θ₁₃ using the ν_e appearance channel. One dominant background to the nue appearance search is the single π⁰ from neutral-current interactions. This background will be measured at the near site using the π⁰ detector. In this talk, we will present the event reconstruction and cosmic ray test of the detector.