The typeⅡclustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas)9 system has been used as a gene-targeting technology as ZFN and TALEN to meditate multiple genome editing. Unlike ZFN and TALEN directly binding to the specific DNA sequence to generate a double-strands break, the engineered CRISPR/Cas9 system has been demonstrated that Cas9 nuclease was directed by short RNAs to induce site-specific cleavage in complex genome. The advantage of CRPSR/Cas9 system is easy to be constructed and low cost compared with ZFN and TALEN. So, it is considered that it will replace existing technique. Here we review the CRISPR/Cas development history, classification, mechanism, progress and application of this new genome editing technology. This review will provide a useful reference for researchers who are interested in applying this new technique in their studies.