The present invention provides a compound represented by the formula: wherein Q represents a fused heterocyclic group, X and Y are the same or different and each represent an optionally halogenated lower alkyl group, an optionally halogenated lower alkoxy group, etc., or a salt thereof, as well as a herbicide comprising the compound or a salt thereof, which exhibits a significant effect for control of sulfonylurea herbicide-resistant weeds in paddy fields and can reduce the number of active ingredients in a combined preparation and a method of controlling sulfonylurea herbicide-resistant weeds which comprises using the same.