The present invention relates to a vector pair for screening tau oligomer formation, a mouse embryo introduced with the vector pair, a transgenic model mouse of neurological disease, obtained from the mouse embryo, and a method of screening a tau oligomer formation inhibitor candidate using the transgenic model mouse. More specifically, the present invention provides vector pair for screening tau oligomer formation, comprising: a first vector comprising a first tau gene, a first fluorescence protein gene and a first neuron-specific promoter; and a second vector comprising a second tau gene, a second fluorescence protein gene and a second neuron-specific promoter, wherein a protein expressed from the first fluorescence protein gene and a protein expressed from the second fluorescence protein gene bind to each other to display fluorescence, by association between a protein expressed from the first tau gene and a protein expressed from the second tau gene.