In　this　study,　pyrochlore　Pr2B2O7　oxides　(B--Zr,　ZrSn,　Sn,　PZO/PZSO/PSO)　and　perovskite　(B--Ti,　PTO)　were　prepared　as　direct　ammonia　solid　oxide　fuel　cell　(DA-SOFC)　cathode　with　oxygen　reduction　reaction　activity　induced　by　B-site　cationic　defects.　Compared　with　PTO,　the　pyrochlore　PBO　with　unoccupied　8a-oxygen　sites　are　high　in　inherent　oxygen　vacancies　(ca.　12.5%),　leading　to　enhanced　migration　of　lattice　oxygen.　Among　the　ntype　semiconductors,　PZO　is　with　a　more　negative　flat-band　potential　and　is　more　effective　in　terms　of　overcoming　energy　barriers.　As　a　result,　the　conductivity　of　PZO　is　two　orders　of　magnitude　higher　than　that　of　PTO　at　800　degrees　C.　The　oxygen　transport　performance　reveals　that　the　surface　exchange　coefficient　of　PZO　is　about　one　order　of　magnitude　higher　than　that　of　La0.7Sr0.3MnO3-delta　at　900　degrees　C.　Owing　to　high　conductivity,　fast　oxygen　transport,　and　matched　thermal　expansion　coefficient,　an　anode-supported　DA-SOFC　using　the　PZO-based　cathode　can　offer　a　maximum　power　density　of　0.25　W　cm-2　at　600　degrees　C　and　1.22　W　cm-2　at　800　degrees　C,　operating　continuously　over　100　h　without　obvious　degradation.　The　electrochemical　performance　is　2.3　folds　higher　than　those　of　SOFCs　using　other　PBO-based　cathode,　and　higher　than　most　reported　SOFCs　with　the　cathodes　using　A-site　Pr.