The redundancy of genes for plant transcription factors often interferes with efforts to identify the biological functions. To overcome such redundancy we have developed a novel gene silencing system by using a dominant repressor, which was designated as CRES-T. We demonstrated feasibility and efficiency of the CRES-T system in several plant transcription factors of different families in transgenic plants. This CRES-T system is simple and effective compared existing gene silencing system and can overcome genetic redundancy. This system would be useful not only for the rapid analysis of the functions of transcription factors but also for the manipulation of plant traits.