Influenza is a major threat to millions of people worldwide.  Vaccines and antiviral agents are two main options available to reduce the impact of the influenza virus, while anti-influenza agents are the most effective means to prevent the transmission of the highly contagious virus and to treat the epidemics of disease.  At present, four anti-influenza agents have been approved by the FDA for the treatment of influenza, including two M2 protein ion channel inhibitors-amantadine and rimantadine and two neuraminidase inhibitors-zanamivir and oseltamivir.  Arbidol hydrochloride, launched in Russia, is a potent inhibitor of influenza virus, too.  Neuraminidase inhibitors could be classified generally by structure into six different kinds: sialic acid derivatives, benzoic acid derivatives, cyclohexene derivatives, cyclopentane derivatives, pyrrolidine derivatives and natural products.  In this paper, recent progress in the research of the action mechanisms and structure-activity      relationships of these anti-influenza virus agents were reviewed.