In vivo electroporation has served as an effective tool for the study of developmental biology. Here we report tetracycline inducible gene knockdown by electroporation. Our system consists of genome integration of a cassette encoding long double strand RNA (dsRNA) of a gene of interest by electroporation, transcription of which is assured by RNA polymerase II, and induction of transcription of dsRNA by tetracyclin. Long dsRNA decapped by ribozyme in the cassette and without poly A tail is processed into siRNA within nuclei. We could successfully induce knockdown of En2 and Coactosin by Dox administration.