The transport properties and fatigue effect of Ag/Bi0.9La0.lFeO3/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.lFeO3 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.lFeO3 interface.