Abstract: Alternaria panax Wheltz is the main leaf disease of Panax notoginseng (Burk.) F H Chen. The average incidence of Alternaria panax ranges from 20% to 35%, even up to 90% in some plantations. To screen the appropriate fungicide for field control, eleven fungicides, including thiram, flusilazle, difenoconazole, propiconazole, debuconazole, chlorothalonil, diniconazole, iprodione, mancozeb, carbendazim, and zoxamide, were selected to determine their toxicity to Alternaria panax with mycelium growth inhibitory method and spore germination inhibitory method. The results showed that EC50 of difenoconazole for pathogen hyphae was 0.004 mg/L, which was the minimum in all fungicides, indicating that difenoconazole was sensitive to Alternaria panax. Propiconazole, debuconazole, flusilazole and diniconazole had better inhibitory activity. Iprodione, chlorothalonil, thiram, zoxamide and mancozeb had worse inhibition activity, While carbendazim had the worst inhibitory activity with EC50 value over 800 mg/L. Spore germination inhibition results showed that mancozeb had the best inhibition activity with the minimum EC50 value of 0.0067 mg/L, while chlorathalonil and thiram had the second inhibition activity with EC50 value as 1.2855 mg/L and 5.2379 mg/L, respectively. Propiconazole, flusilazole, difenoconazole, and iprodione had normal inhibition activity with EC50 value ranged from 10.6469 mg/L to 25.0169 mg/L. Zoxamide and carbendazim had less inhibition activity with EC50 valueas 106.1958 mg/Land 199.9349 mg/L, respectively. EC50 value of debuconazole and diniconazole to Alternaria panax were 300 mg/L, and the inhibition activity was the worst.