Oxide transistor is the basic device to construct the oxide electronic circuit that is the backing to develop integrated oxide electronics with high efficiency and low power consumption.By growing the perovskite oxide integrated layers and tailoring them to lead semiconducting functions at their interfaces,the development of oxide transistors may be able to perform.We realize a kind of p- i-n type integrated layers consisting of an n-type cuprate superconductor,p-type colossal magnetoresistance manganite,and a ferroelectric barrier (i).From this,bipolar transistors were fabricated at the back-to-back p-i-n junctions,for which the Schottky emission and p-n junction barriers,as well as the ferroelectric polarization,were integrated into the interfaces to control the transport properties;a preliminary but distinct current gain greater than 1.6 at input current of microampers order was observed.These results present a real possibility to date for developing bipolar all perovskite oxide transistors.