The invention provides new application of erucic acid in preparing a medicine for preventing or treating vaccinum influenzae vivum. The invention also provides the medicine for preventing or treatingvaccinum influenzae vivum. The medicine is prepared from the active ingredient erucic acid. The inventor finds that the erucic acid has remarkable inhibitory activity on vaccinum influenzae vivum replicated and mediated inflammatory reaction. A liquid chip technology is adopted to prove that the erucic acid can remarkably inhibit the abnormal expression of an H1N1 virus infected A549 cell inflammatory factor and is in a dose-dependent relationship; an immunoblotting method is adopted to prove that the erucic acid can inhibit activation of a host inflammation-associated signal path and is in adose-dependent relationship; Annexin V-FITC/PI double-tagging flow cytometry is adopted to prove that the erucic acid can remarkably inhibit apoptotic lesion of a flue H1N1 induced host cell and is ina dose-dependent relationship. Animal experiments prove that the erucic acid can remarkably inhibit lung inflammation and apoptotic lesion induced by vaccinum influenzae vivum H1N1, and the survivaltime of rats is effectively prolonged.