It is widely accepted that RNA silencing or RNA interference plays a crucial role in defending viruses from invasion and regulating gene expression, and has become a very potent tool for genetic function studies and some disease therapies. RNA silencing ubiquitously exists in eukaryotic cells, however, during the boundless process of synergistic evolution for the host and viruses, viruses have gained capacities of escaping or suppressing RNA silencing to make RNA interference sterile. On the other hand, some studies have revealed that mammiferous cells themselves also could regulate the effects of RNA silencing, which presents the regulation of vital activities under a more perfect condition. In order to develop the potential function of RNA silencing, people have worked out a number of strategies to decrease the suppression effects of RNA silencing. Here, all kinds of suppress mechanisms and application about RNA silencing were summarized in order to make people take cognizance of the disadvantage of RNA silencing technology while using it.