Abstract:  First,we give the notion of set under the figure(ordinary set)and its operative lows.Second,it is proved that system (I²:V 、A 、,) of fuzzy sets is isomorphic with the system (K(X);∩,U,c)of sets under the figure.Therefore we can denote fuzzy set and fuzzy relation by ordinary sets.Thus one showed new thought and new method to study deeply fuzzy set and fuzzy relation.

Key words: set under the figure, relationship