The conventional von-Neumann architecture,which physically separates processing and memory operations,is limited so much as the processor cannot execute a program faster than instructions and data can be fetched from and returned to,memory,leading to the well-known von-Neumann bottleneck.[1] Memristive switches are the leading candidate for the next generation memories and nonvolatile logic applications,which can be used to overcome the von-Neumann bottleneck thanks to the possibility to carry out the processing and storage simultaneously at the same resistive switching devices.[2,3] Recently,BiFeO3(BFO)based memristive switches have attracted increasing attention due to the fascinating resistive switching performance,e.g.electroforming free,multilevel resistive switching.[4,5] In this work,BFO based MIM structures were fabricated on Sapphire substrates with Ti-implanted Pt bottom electrodes.The resulting MIM structures show bipolar resistive switching without electroforming process.It is evidenced that the Ti diffusion into the BFO layer is crucial for the resistive switching which can be engineered by Ti implantation of the bottom electrodes.The diffused Ti effectively traps and releases oxygen vacancies and consequently stabilizes the resistive switching in BFO MIM structures.The retention performance can be greatly improved with increasing Ti fluence while for the used raster-scanned Ti implantation the lateral Ti distribution is not homogeneous enough and endurance slightly degrades with increasing Ti fluence.The local resistive switching investigated by current sensing atomic force microscopy suggests the capability of down-scaling the resistive switching cell to the size of single BFO crystallites.