RNA interference (RNAi), a new gene silencing technique during recent years, is a post transcriptional gene silencing mediated by double stranded RNA which results in the sequence-specific silence of target gene. RNAi provides several major advantages over prior methods such as antisense DNA or antibody-based techniques for suppressing gene expression. In mammalian cells, RNAi can be triggered by 21-25 nucleotide duplexes of small interfering RNA (siRNA). The use of RNAi in mammals as a tool to study gene function has rapidly developed in recent years. In the post-genome era, RNAi has broad application prospect in probing gene function and drug research. RNAi technique has been applied widely in the research of various tumors and neurodegeneration diseases. The recent advances in the mechanism of RNAi as well as its use in the research of intervertebral disc degeneration (IVDD) were reviewed.