RNA interference (RNAi) is the most exciting insight in biology in past decades, which provided new perspectives into the genome-wide surveys of gene function by targeted degradation of mRNA with the introduction of small interfering RNAs (siRNAs) or small hairpin RNAs (shRNAs) in a large variety of organisms, and turned out to be a more efficient and convenient method compared with the traditional knockout pathway. What's more, as the enhancement of its stability and improvement of its delivery vehicles, RNAi is bound to be a practical tool in determine gene function first in vitro and then in vivo. In this paper, we will focus on the recent achievements of RNAi and also depict the development of RNAi as a potentially powerful tool in studying bone-related diseases. (C) 2007 Elsevier Inc. All rights reserved.