A method for inducing activity of a specific RNAi into eukaryote cells in which the TAT protein and a nucleic acid coding for a nucleotide sequence comprising the sense and antisense sequences of an RNAi of interest are introduced, which sense and antisense sequences are separated by a separating nucleotide sequence coding for a sequence comprising at least the minimal TAR sequence recognized by the TAT protein, which transcribed separating sequence and the TAT protein form a complex that inhibits the activity of the RNAi of interest, and the activity of the RNAi is induced by withdrawing the TAT protein.