RNA interference (RNAi) is a gene-silencing progress induced by double stranded RNA at a level of posttranscription. At present, RNAi has been extensively applied to the research domain of gene functions and disease therapies, especially for the therapy of malignant tumours due to its simple designs, immediate effects and obvious efficiency. Up to now, a number of novel strategies have been engineered to effectively fight against malignancies through RNAi technology in the regulation of the tumorigenesis-and-progression-associated genes. Presently, uncontrolled RNA Pol Ⅲ promoter expressing classical small hairpin RNA which can be processed into siRNA by Dicer enzyme is extensively applied. However, most of the current methods lack of tumor targeting and high efficiency in cancer therapy. The latest studies have demonstrated that RNAi induced by the tissue specific RNA Pol Ⅱ promoter could compensate for a deficiency of RNAi mediated by RNA Pol Ⅲ promoter. Moreover, virus vectors, especially cancer-specific replicable adenovirus targeting to cancer cells and oncolysising, which can express siRNA controlled by RNA Pol Ⅱ promoter, is expected to be a more effective therapy strategy.