An epidemic of human H7N9 influenza virus infection has recently emerged in China, which was clinically featuring with high mortality and while also resulting in serious economic loss. The novel reassortant avian-origin influenza A (H7N9) virus, as the causative agent of this epidemic, raised the possibility of triggering a large-scale of flu pandemic worldwide. It seemed likely that fast molecular detection assays specific for this viruses would be in great demand. Here we report a one-step RT-LAMP method for rapid detection of HA gene and NA gene of H7N9 virus, the minimum detection limit of which was evaluated using in vitro transcription RNA templates. Totally, 135 samples from clinical specimens (from either patients or poultry) were subjected to testing by this method in comparison with the real time PCR recommend by the World Health Organization (WHO). Our results showed that 1) RT-LAMP-based trials can be completed in 12～23 minute, 2) detection limit for H7 gene is around 10 copies per reaction, which is similar to that of the real time PCR whereas that for its counterpart N9 gene is 5 copies per reaction with a 100-fold higher sensitivity than the WHO recommended-method. Indeed, this excellent performance of our method was also validated by a series of clinical specimens. Therefore we believe that the simple, fast and sensitive method of RT-LAMP might be widely applied in the field detection for H7N9 infections and play a role in prevention of an influenza pandemic.