The transport properties and fatigue effect of Ag/Bi0.9La0.1FeO3/La0.7Sr0.3MnO3 heterostructures are described. By examining the I–V curves, an anomalous fatigue effect was found and its influences on resistive states were studied. I–V curves combined with C– f spectra were used to directly analyze the transport properties and fatigue effect. Compared to the first I–V cycle state, this structure shows more than one order increase of resistance after 100 cycles of "I–V curve training". The redistribution of oxygen vacancies in the depletion layer of Ag/Bi0.9La0.1FeO3 is believed to be responsible for the different resistance mechanisms and tenfold magnitude drop in resistance. The resistive switching is understood to be caused by electric field–induced carrier trapping and detrapping, which changes the depletion layer thickness at the Ag/Bi0.9La0.1FeO3 interface.