RNA interference（RNAi） is a post-transcriptional gene silencing mechanism mediated by double stranded RNA（dsRNA）. As an efficient gene suppression technology,RNAi has been widely used in crop genetic improvement,such as the resistance of disease and insects,the improvement of crop quality,and the tolerance of abiotic stresses. When assessing the ecological risk assessment of RNAi crops,we should pay more attention to off-target effects,non-target effects,environmental fate of dsRNA molecules and other unexpected effects. This review summarized the application status of RNAi technology in crop breeding,discussed the key problems and procedures of ecological risk assessment of RNAi crops,and prospected the future research and safety assessment of RNAi crops in China.