Novel substituted thiophenesulfonamide compounds useful as herbicides which are represented by the following formula, and salts thereof: ##STR1## wherein either one of X and Y is an ethenyl or propenyl group having all hydrogen atoms replaced by chlorine atoms and/or fluorine atoms, and the other is the group ##STR2## (wherein R.sub.1 and R.sub.2 are each a methyl or methoxy group, and A is .dbd.N-- or .dbd.CH--).