HIV-1 cell entry is a multi-step process that is an attractive target for the development of new classes of therapeutic agents.HIV-1 cell entry inhibitors include a variety of drugs with different points of attack and with the common objective of preventing the entry of HIV into the cell.In our laboratory,we have synthesized and expressed two kinds of cell entry inhibitors of HIV-1:M21 and C22.M21 is an active fragment of mung bean trypsin inhibitor which is an effective inhibitor for furin.Mammalian finin is a kind of protein convertase involved in the proteolytic processing of many important precursor proteins such as HIV-1 gp160.C22 is a new fusion inhibitor based on the sequence of C-terminal of HIV-1 gp41,which can react with the N-terminal of gp41,and then inhibit the HIV-1 cell entry.