A novel compound (I) represented by the following formula (1) is provided which is suitable for a dental composition and has a polymerizable group, a carboxyl group and a phosphoric acid group. A method for producing a polymerizable amide is provided, which method can make a condensation reaction of a carboxylic acid with an amine to proceed easily and is excellent in safety: wherein R.sup.1, R.sup.2 and R.sup.3 each independently are a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent; (A) and (B) are each any constituent unit; m is an integer of from 1 to 3; n is an integer of from 1 to 3; R.sup.4 is an organic group having 1 to 40 carbon atoms which may have a substituent; R.sup.5 is a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, R.sup.6 and R.sup.7 each independently are a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, or a metal atom. ##STR00001##