The present invention provides a method for assessing sensitivity of a rice blast fungus to a scytalone dehydratase inhibitor, comprising the steps of: (a) and (b), which (a) identifies an amino acid in an amino acid sequence of a scytalone dehydratase isolated from the rice blast fungus, where the amino acid corresponds to valine at position 75 of SEQ ID NO: 4; and (b) assesses the sensitivity of the rice blast fungus to the scytalone dehydratase inhibitor, where if the amino acid identified in step (a) is methionine, the sensitivity of the rice blast fungus to The scytalone dehydratase inhibitor is assessed to be lower than that of a wild-type rice blast fungus which endogenously produces the scytalone dehydratase of SEQ ID NO: 4.