Ribosome is a molecular machine based on RNA,which provides the workshop and tools to synthesize all of the proteins in cells.Its sophisticated structure enables crystallographers regarding it as the Mount Everest for a long time.Recently ,the breakthrough has made for ribosome structure studies.For the first time,several proteins of known three-dimensional structure,and many regions of double-stranded rRNA,have been located in highly complex electron-density maps of ribosomal subunits. And the delicate structure of subunit interface and complicated tRNA,mRNA and ribosome interactions have been revealed.