Despite of many year scientific research efforts, so far there is no clinical available inhibitor against HA1. On the other hand, many studies have indicated that computational approaches, such as structural bioinformatics [24, 25] , molecular docking [26, 27] , pharmacophore modeling [28] , identification of proteases and their types [29] , and HIV protease cleavage site prediction [30, 31] , can timely provide very useful information and insights for drug development. Encouraged by the aforementioned studies, the present study was initiated in an attempt to find a new antiinfluenza compound by screening the fragment database for the optimal constituent inhibitor. Meanwhile, the techniques of the core hopping with glide docking and molecular dynamic simulation were also utilized to analyze the binding interactions between the inhibitor and HA1, in hopes that the findings thus obtained will be useful for developing new and powerful drugs against H1N1 influenza virus.