Abstract: The synergistic effects of Myclobutanil and Thiophanate-methyl and their mixtures-made up by mixing the two pesticides in different ratios , on Alternaria mali Roberts and Physalospora piricola and Glomerella cingulata were tested by mycelial growth rate method. Experimental results demonstrated that Myclobutanil mixed with Thiophanate-methyl in 1:8 and1:12 had significant synergism to Physalospora piricola and Glomerella cingulata on Apple than used alone. The efficiency coefficient on the two Fungi were 2.88;2.21. The efficiency coefficient of five different ratios on Alternaria mali were less than 0.5 which were showed antagonism.