The invention relates to an amide derivative and a purpose thereof. The invention discloses an N-(4-substiguted aminoacyl phenyl)-5-substited furan-2-formamide compound and tests the activity of the compound for inhibiting falcipain-2 in experiment of enzyme level in vitro, and the result indicates that the compound has strong inhibitory activity to falcipain- 2. Therefore, the N-(4-substiguted aminoacyl phenyl)-5-substited furan-2-formamide compound provided in the invention can act as cysteine protease (falcipain-2) inhibitor in food vacuole of plasmodium to stop further proliferation of plasmodium in a host.