Alzheimer’s disease is the most common form of neurodegenerative disease that leads to a progressive loss of memory and cognitive functions. Increasing evidence indicates that beta-amyloid oligomers are pivotal toxins in the pathogenesis of Alzheimer's disease. In this study, W20, a single-chain variable fragment antibody specifically recognizing beta-amyloid oligomers was cloned to pSNAV2.0-EGFP vector and its expression in 293T cells was examined by flow cytometry, western blot and fluorescence microscope. Such scFv antibody eukaryotic expression vectors may have valuable application in the further investigation of AD gene therapy in vivo.