The invention of this application provides a method comprising introducing a reporter nucleic acid molecule that expresses a fluorescent protein under control of the promoter/enhancer of a gene that is expressed in dopaminergic neurons, into each of cells, and isolating fluorescence-emitting cells. The invention also provides a method for visualizing and identifying dopaminergic neurons alive that exist with in cells, which comprises introducing the above-mentioned reporter nucleic acid molecule into each of cells, and measuring the fluorescence distribution within the cells. The invention further provides a method for identifying a dopaminergic neurons-inducing factor, which comprises introducing the reporter nucleic acid molecule into cells that have the ability to differentiate into dopaminergic neurons, then incubating the cells with a candidate substance, and determining whether the candidate substance is a dopaminergic neurons-inducing factor by using the fluorescence of the cells as an indicator.