In　this　paper,　the　off-morphotropic-phase-boundary　74(Bi1/2Na1/2)TiO3-20.8(Bi1/2K1/2)TiO3-5.2BaTiO(3)　ceramics　were　fabricated　at　different　sintering　temperatures.　It　was　found　out　that　as　the　sintering　temperature　increases,　the　volatilization　of　the　A-site　elements　is　aggravated,　thus　generating　the　oxygen　vacancies;　meanwhile,　the　tetragonality　of　the　perovskite　lattice　reduces　gradually.　Besides,　the　temperature-dependent　dielectric　responses　revealed　that　as　the　sintering　temperature　increases,　the　depolarization　temperature　T-d　decreases　while　the　Curie-Weiss　point　T-C　increases.　It　is　suggested　that　the　lattice　distortion,　other　than　the　oxygen　vacancies,　is　the　crucial　factor　in　influencing　the　depolarization　temperature.