To screen effectual fungicides for field control because of the seriousness of opium poppy mildew and importance of chemical control on plant diseases.Seven fungicides were screened in Lab experiment and field test during 1996-1997.All of them and their different dosages were effective to control conidia of Peronospora arborescens. Among them, 72.2% propamocarb of 1203 and 902.5 ppm were the most effective both in Lab experiment and field test with efficacy 79.91% and 79.33% respectively in field test, and the efficacy of other fungicides was over 50%. Seven fungicides tested can be used to control nonsystematic symptom of opium poppy mildew.